cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

Showing 1-4 of 4 results.

A100195 Numbers n such that the denominator of BernoulliB(n) is a record.

Original entry on oeis.org

0, 1, 2, 4, 6, 10, 12, 30, 36, 60, 72, 108, 120, 144, 180, 240, 360, 420, 540, 840, 1008, 1080, 1200, 1260, 1620, 1680, 2016, 2160, 2520, 3360, 3780, 5040, 6480, 7560, 8400, 10080, 12600, 15120, 25200, 30240, 42840, 45360, 55440, 60480, 75600, 85680, 100800
Offset: 1

Views

Author

Eric W. Weisstein, Nov 08 2004

Keywords

Crossrefs

Cf. A100194 (the corresponding Bernoulli denominators), A000367/A002445.

Programs

  • Mathematica
    DeleteDuplicates[Table[{n,Denominator[BernoulliB[n]]},{n,0,101000}],GreaterEqual[#1[[2]],#2[[2]]]&][[;;,1]] (* Harvey P. Dale, Jul 22 2025 *)
  • PARI
    b(n) = if((n==0) || (n>1 && n%2==1), 1, my(d=divisors(n)); prod(k=1, #d, if(isprime(d[k]+1), d[k]+1, 1))); \\ more efficient than denominator(bernfrac(n))
    lista(n) = { my(m=0); for(k=0, n, my(d=b(k)); if(d>m, m=d; print1(k, ", "))); }
    lista(100000); \\ Daniel Suteu, Dec 23 2018

Extensions

Corrected and extended by Daniel Suteu, Dec 23 2018

A281386 Incrementally largest numerators of the Bernoulli numbers.

Original entry on oeis.org

1, 5, 7, 43867, 854513, 8553103, 8615841276005, 2929993913841559, 1520097643918070802691, 596451111593912163277961, 495057205241079648212477525, 29149963634884862421418123812691, 84483613348880041862046775994036021, 12300585434086858541953039857403386151
Offset: 1

Views

Author

Seiichi Manyama, Jan 21 2017

Keywords

Crossrefs

Cf. A100194 (denominator), A000367/A002445.

A114649 Denominators of BernoulliB ranked by frequency of occurrence.

Original entry on oeis.org

6, 30, 42, 66, 510, 138, 798, 2730, 870, 282, 330, 354, 1806, 498, 1590
Offset: 1

Views

Author

Eric W. Weisstein, Dec 21 2005

Keywords

Comments

a(n+1) mod 9 = 6, 3, 6, 3, 6, 3, 6, 3, 6, 3, 6, 3, 6, 3, 6 which appears to be A010704(n+1). - Paul Curtz, Oct 28 2012

Crossrefs

Extensions

Additional 10 terms from Eric W. Weisstein link, Oct 28 2012

A281585 Incrementally largest numerators of |Bernoulli(n)|.

Original entry on oeis.org

1, 5, 691, 3617, 43867, 174611, 854513, 236364091, 23749461029, 8615841276005, 26315271553053477373, 261082718496449122051, 1520097643918070802691, 27833269579301024235023, 596451111593912163277961, 5609403368997817686249127547
Offset: 1

Views

Author

Seiichi Manyama, Jan 25 2017

Keywords

Crossrefs

Cf. A100194 (denominator), A281386.

Programs

  • Mathematica
    DeleteDuplicates[Abs[Numerator[BernoulliB[Range[50]]]],GreaterEqual] (* Harvey P. Dale, Sep 07 2023 *)
Showing 1-4 of 4 results.