Summing Bernoulli numbers

The name of the pictureThe name of the pictureThe name of the pictureClash Royale CLAN TAG#URR8PPP











up vote
6
down vote

favorite
3












Consider the Bernoulli numbers denoted by $B_n$, which are rational numbers.



It is known that the harmonic numbers $H_n=sum_k=1^nfrac1k$ are not integers once $n>1$.



I am curious about the following:




Question: If $n>0$, will $sum_k=0^nB_k$ ever be an integer?








share|cite|improve this question
























    up vote
    6
    down vote

    favorite
    3












    Consider the Bernoulli numbers denoted by $B_n$, which are rational numbers.



    It is known that the harmonic numbers $H_n=sum_k=1^nfrac1k$ are not integers once $n>1$.



    I am curious about the following:




    Question: If $n>0$, will $sum_k=0^nB_k$ ever be an integer?








    share|cite|improve this question






















      up vote
      6
      down vote

      favorite
      3









      up vote
      6
      down vote

      favorite
      3






      3





      Consider the Bernoulli numbers denoted by $B_n$, which are rational numbers.



      It is known that the harmonic numbers $H_n=sum_k=1^nfrac1k$ are not integers once $n>1$.



      I am curious about the following:




      Question: If $n>0$, will $sum_k=0^nB_k$ ever be an integer?








      share|cite|improve this question












      Consider the Bernoulli numbers denoted by $B_n$, which are rational numbers.



      It is known that the harmonic numbers $H_n=sum_k=1^nfrac1k$ are not integers once $n>1$.



      I am curious about the following:




      Question: If $n>0$, will $sum_k=0^nB_k$ ever be an integer?










      share|cite|improve this question











      share|cite|improve this question




      share|cite|improve this question










      asked Sep 6 at 18:23









      T. Amdeberhan

      15.7k225119




      15.7k225119




















          2 Answers
          2






          active

          oldest

          votes

















          up vote
          12
          down vote



          accepted










          It can never be an integer for $n>0$. There is a result by K.G.C. von Staudt and independently by T. Clausen that
          $$B_n+sum_nfrac1pin mathbb Z$$




          [1] T. Clausen. Lehrsatz aus einer Abhandlung uber die Bernoullischen Zahlen.
          Astr. Nachr., 17:351–352, 1840



          [2] K. G. C. von Staudt. Beweis eines Lehrsatzes die Bernoulli'schen Zahlen
          betreffend. J. Reine Angew. Math., 21:372–374, 1840




          Using this we see that the integrality of $sum_k=0^n B_k$ is equivalent to the integrality of
          $$sum_k=2^nleft(sum_pin mathbb P , , , p-1frac1pright)=sum_pin mathbb Pfraclfloorfracnp-1rfloorp$$
          If $q$ is the largest prime $le n$ we have $lfloor fracnq-1rfloor =1$ therefore our expression has $q$-valuation $-1$, so is not an integer.






          share|cite|improve this answer




















          • Thank you, Gjergji.
            – T. Amdeberhan
            Sep 7 at 17:17

















          up vote
          8
          down vote













          It is never an integer. By Bertrand postulate there exists a prime $p=2s+1$ between $n/2$ and $n$, it divides the denominator of $B_p-1$ and not of other summands in your sum, by von Staudt - Clausen Theorem.






          share|cite|improve this answer




















          • Thank you, Fedor.
            – T. Amdeberhan
            Sep 7 at 13:20










          Your Answer




          StackExchange.ifUsing("editor", function ()
          return StackExchange.using("mathjaxEditing", function ()
          StackExchange.MarkdownEditor.creationCallbacks.add(function (editor, postfix)
          StackExchange.mathjaxEditing.prepareWmdForMathJax(editor, postfix, [["$", "$"], ["\\(","\\)"]]);
          );
          );
          , "mathjax-editing");

          StackExchange.ready(function()
          var channelOptions =
          tags: "".split(" "),
          id: "504"
          ;
          initTagRenderer("".split(" "), "".split(" "), channelOptions);

          StackExchange.using("externalEditor", function()
          // Have to fire editor after snippets, if snippets enabled
          if (StackExchange.settings.snippets.snippetsEnabled)
          StackExchange.using("snippets", function()
          createEditor();
          );

          else
          createEditor();

          );

          function createEditor()
          StackExchange.prepareEditor(
          heartbeatType: 'answer',
          convertImagesToLinks: true,
          noModals: false,
          showLowRepImageUploadWarning: true,
          reputationToPostImages: 10,
          bindNavPrevention: true,
          postfix: "",
          noCode: true, onDemand: true,
          discardSelector: ".discard-answer"
          ,immediatelyShowMarkdownHelp:true
          );



          );













           

          draft saved


          draft discarded


















          StackExchange.ready(
          function ()
          StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmathoverflow.net%2fquestions%2f310020%2fsumming-bernoulli-numbers%23new-answer', 'question_page');

          );

          Post as a guest






























          2 Answers
          2






          active

          oldest

          votes








          2 Answers
          2






          active

          oldest

          votes









          active

          oldest

          votes






          active

          oldest

          votes








          up vote
          12
          down vote



          accepted










          It can never be an integer for $n>0$. There is a result by K.G.C. von Staudt and independently by T. Clausen that
          $$B_n+sum_nfrac1pin mathbb Z$$




          [1] T. Clausen. Lehrsatz aus einer Abhandlung uber die Bernoullischen Zahlen.
          Astr. Nachr., 17:351–352, 1840



          [2] K. G. C. von Staudt. Beweis eines Lehrsatzes die Bernoulli'schen Zahlen
          betreffend. J. Reine Angew. Math., 21:372–374, 1840




          Using this we see that the integrality of $sum_k=0^n B_k$ is equivalent to the integrality of
          $$sum_k=2^nleft(sum_pin mathbb P , , , p-1frac1pright)=sum_pin mathbb Pfraclfloorfracnp-1rfloorp$$
          If $q$ is the largest prime $le n$ we have $lfloor fracnq-1rfloor =1$ therefore our expression has $q$-valuation $-1$, so is not an integer.






          share|cite|improve this answer




















          • Thank you, Gjergji.
            – T. Amdeberhan
            Sep 7 at 17:17














          up vote
          12
          down vote



          accepted










          It can never be an integer for $n>0$. There is a result by K.G.C. von Staudt and independently by T. Clausen that
          $$B_n+sum_nfrac1pin mathbb Z$$




          [1] T. Clausen. Lehrsatz aus einer Abhandlung uber die Bernoullischen Zahlen.
          Astr. Nachr., 17:351–352, 1840



          [2] K. G. C. von Staudt. Beweis eines Lehrsatzes die Bernoulli'schen Zahlen
          betreffend. J. Reine Angew. Math., 21:372–374, 1840




          Using this we see that the integrality of $sum_k=0^n B_k$ is equivalent to the integrality of
          $$sum_k=2^nleft(sum_pin mathbb P , , , p-1frac1pright)=sum_pin mathbb Pfraclfloorfracnp-1rfloorp$$
          If $q$ is the largest prime $le n$ we have $lfloor fracnq-1rfloor =1$ therefore our expression has $q$-valuation $-1$, so is not an integer.






          share|cite|improve this answer




















          • Thank you, Gjergji.
            – T. Amdeberhan
            Sep 7 at 17:17












          up vote
          12
          down vote



          accepted







          up vote
          12
          down vote



          accepted






          It can never be an integer for $n>0$. There is a result by K.G.C. von Staudt and independently by T. Clausen that
          $$B_n+sum_nfrac1pin mathbb Z$$




          [1] T. Clausen. Lehrsatz aus einer Abhandlung uber die Bernoullischen Zahlen.
          Astr. Nachr., 17:351–352, 1840



          [2] K. G. C. von Staudt. Beweis eines Lehrsatzes die Bernoulli'schen Zahlen
          betreffend. J. Reine Angew. Math., 21:372–374, 1840




          Using this we see that the integrality of $sum_k=0^n B_k$ is equivalent to the integrality of
          $$sum_k=2^nleft(sum_pin mathbb P , , , p-1frac1pright)=sum_pin mathbb Pfraclfloorfracnp-1rfloorp$$
          If $q$ is the largest prime $le n$ we have $lfloor fracnq-1rfloor =1$ therefore our expression has $q$-valuation $-1$, so is not an integer.






          share|cite|improve this answer












          It can never be an integer for $n>0$. There is a result by K.G.C. von Staudt and independently by T. Clausen that
          $$B_n+sum_nfrac1pin mathbb Z$$




          [1] T. Clausen. Lehrsatz aus einer Abhandlung uber die Bernoullischen Zahlen.
          Astr. Nachr., 17:351–352, 1840



          [2] K. G. C. von Staudt. Beweis eines Lehrsatzes die Bernoulli'schen Zahlen
          betreffend. J. Reine Angew. Math., 21:372–374, 1840




          Using this we see that the integrality of $sum_k=0^n B_k$ is equivalent to the integrality of
          $$sum_k=2^nleft(sum_pin mathbb P , , , p-1frac1pright)=sum_pin mathbb Pfraclfloorfracnp-1rfloorp$$
          If $q$ is the largest prime $le n$ we have $lfloor fracnq-1rfloor =1$ therefore our expression has $q$-valuation $-1$, so is not an integer.







          share|cite|improve this answer












          share|cite|improve this answer



          share|cite|improve this answer










          answered Sep 6 at 18:42









          Gjergji Zaimi

          58.7k3153291




          58.7k3153291











          • Thank you, Gjergji.
            – T. Amdeberhan
            Sep 7 at 17:17
















          • Thank you, Gjergji.
            – T. Amdeberhan
            Sep 7 at 17:17















          Thank you, Gjergji.
          – T. Amdeberhan
          Sep 7 at 17:17




          Thank you, Gjergji.
          – T. Amdeberhan
          Sep 7 at 17:17










          up vote
          8
          down vote













          It is never an integer. By Bertrand postulate there exists a prime $p=2s+1$ between $n/2$ and $n$, it divides the denominator of $B_p-1$ and not of other summands in your sum, by von Staudt - Clausen Theorem.






          share|cite|improve this answer




















          • Thank you, Fedor.
            – T. Amdeberhan
            Sep 7 at 13:20














          up vote
          8
          down vote













          It is never an integer. By Bertrand postulate there exists a prime $p=2s+1$ between $n/2$ and $n$, it divides the denominator of $B_p-1$ and not of other summands in your sum, by von Staudt - Clausen Theorem.






          share|cite|improve this answer




















          • Thank you, Fedor.
            – T. Amdeberhan
            Sep 7 at 13:20












          up vote
          8
          down vote










          up vote
          8
          down vote









          It is never an integer. By Bertrand postulate there exists a prime $p=2s+1$ between $n/2$ and $n$, it divides the denominator of $B_p-1$ and not of other summands in your sum, by von Staudt - Clausen Theorem.






          share|cite|improve this answer












          It is never an integer. By Bertrand postulate there exists a prime $p=2s+1$ between $n/2$ and $n$, it divides the denominator of $B_p-1$ and not of other summands in your sum, by von Staudt - Clausen Theorem.







          share|cite|improve this answer












          share|cite|improve this answer



          share|cite|improve this answer










          answered Sep 6 at 18:41









          Fedor Petrov

          44.6k5107211




          44.6k5107211











          • Thank you, Fedor.
            – T. Amdeberhan
            Sep 7 at 13:20
















          • Thank you, Fedor.
            – T. Amdeberhan
            Sep 7 at 13:20















          Thank you, Fedor.
          – T. Amdeberhan
          Sep 7 at 13:20




          Thank you, Fedor.
          – T. Amdeberhan
          Sep 7 at 13:20

















           

          draft saved


          draft discarded















































           


          draft saved


          draft discarded














          StackExchange.ready(
          function ()
          StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmathoverflow.net%2fquestions%2f310020%2fsumming-bernoulli-numbers%23new-answer', 'question_page');

          );

          Post as a guest













































































          Comments

          Popular posts from this blog

          Long meetings (6-7 hours a day): Being “babysat” by supervisor

          Is the Concept of Multiple Fantasy Races Scientifically Flawed? [closed]

          Confectionery