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.

A187651 Alternated binomial partial sums of the central Stirling numbers of the second kind.

Original entry on oeis.org

1, 0, 6, 71, 1380, 34854, 1092317, 40900215, 1781924888, 88569337730, 4946558473226, 306691008191732, 20903038895529727, 1553426761730508586, 125016067017985968931, 10831572432055401760624, 1005245087722396707881648
Offset: 0

Views

Author

Emanuele Munarini, Mar 12 2011

Keywords

Crossrefs

Cf. A187653.

Programs

  • Maple
    seq(add((-1)^(n-k)*binomial(n,k)*combinat[stirling2](2*k,k), k=0..n), n=0..20);
  • Mathematica
    Table[Sum[(-1)^(n-k)Binomial[n, k] StirlingS2[2k, k], {k, 0, n}], {n, 0, 16}]
  • Maxima
    makelist(sum((-1)^(n-k) *binomial(n,k) *stirling2(2*k,k), k,0,n), n,0,12);

Formula

a(n) = Sum_{k=0..n} (-1)^(n-k)*binomial(n,k)*S(2*k,k).
a(n) ~ c * d^n * (n-1)!, where d = 4/(w*(2-w)) = 6.176554609483480358231680164... and c = exp(w^2/4 - 1) / (Pi * sqrt(2*w * (1-w))) = 0.17569156962762991098958896633434384684339835018075095823375851..., where w = -LambertW(-2*exp(-2))^2 = -A226775. - Vaclav Kotesovec, Mar 30 2018, updated Jul 07 2021