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 1-2 of 2 results.

A239793 Denominator of b_{2n}(1/4), where b_{n}(x) are Nörlund's generalized Bernoulli polynomials.

Original entry on oeis.org

1, 24, 320, 10752, 184320, 360448, 23855104, 94371840, 285212672, 267764367360, 3720515420160, 987842478080, 201004469452800, 103903848824832, 637716744110080, 11997870882291712, 368450744514248704, 2251799813685248, 164633587978155851776, 9367487224930631680
Offset: 0

Views

Author

Peter Luschny, Mar 26 2014

Keywords

Comments

See A239792 for references.

Crossrefs

Cf. A220412, A239792 (numerators).

Programs

  • Maple
    b := proc(n) option remember; if n < 1 then 1 else
    -add(binomial(n-1, k-1)*bernoulli(k)*b(n-k)/k, k= 2..n)/2 fi end:
    A239793 := n -> denom(b(2*n));
    seq(A239793(n), n=0..19);
  • Mathematica
    b[n_] := b[n] = If[n < 1, 1, -Sum[Binomial[n - 1, k - 1] BernoulliB[k] b[n - k]/k, {k, 2, n}]/2];
    a[n_] := b[2 n] // Denominator;
    Table[a[n], {n, 0, 19}] (* Jean-François Alcover, Jun 28 2019 *)

Formula

Let b(n) = -sum_{2<=k<=n}(C(n-1, k-1)*Bernoulli(k)*b(n-k)/k)/2 for n>0 and otherwise 1. Then a(n) = denominator(b(2*n)).

A239795 a(n) = A239793(n)/2^(3*n).

Original entry on oeis.org

1, 3, 5, 21, 45, 11, 91, 45, 17, 1995, 3465, 115, 2925, 189, 145, 341, 1309, 1, 9139, 65, 2255, 148995, 108675, 1645, 270725, 21879, 583, 4389, 4959, 59, 1548729, 27027, 60775, 130985, 15525, 1065, 66047553, 2567565, 39, 2133, 56457, 1411, 8161615, 2639
Offset: 0

Views

Author

Peter Luschny, Mar 26 2014

Keywords

Comments

See A239792 for references.

Crossrefs

Programs

  • Maple
    b := proc(n) option remember; if n < 1 then 1 else
    -add(binomial(n-1, k-1)*bernoulli(k)*b(n-k)/k, k= 2..n)/2 fi end:
    A239795 := n -> denom(b(2*n))/2^(3*n):
    seq(A239795(n), n=0..43);

Formula

Let b(n) = -Sum_{2<=k<=n} (C(n-1, k-1)*Bernoulli(k)*b(n-k)/k)/2
for n>0 and otherwise 1. Then a(n) = denominator(b(2*n))/2^(3*n).
Showing 1-2 of 2 results.