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.

A187650 Alternated cumulative sums of the (signless) central Stirling numbers of the first kind (A187646).

Original entry on oeis.org

1, 0, 11, 214, 6555, 262770, 13076765, 777866388, 53853263165, 4254252038764, 377667803463431, 37222867283396314, 4033161189724173207, 476511397553009371918, 60969023704806106263737, 8398605422371512041566888
Offset: 0

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Author

Emanuele Munarini, Mar 12 2011

Keywords

Crossrefs

Programs

  • Maple
    seq(sum((-1)^(n-k)*abs(combinat[stirling1](2*k,k)),k=0..n),n=0..12);
  • Mathematica
    Table[Sum[(-1)^(n-k)Abs[StirlingS1[2k, k]], {k, 0, n}], {n, 0, 15}]
  • Maxima
    makelist(sum((-1)^(n-k)*abs(stirling1(2*k,k)),k,0,n),n,0,12);

Formula

a(n) = Sum_{k=0..n} (-1)^(n-k)*s(2*k,k).
a(n) ~ 2^(3*n-1) * c^(2*n) * n^(n - 1/2) / (sqrt(Pi*(c-1)) * (2*c-1)^n * exp(n)), where c = -LambertW(-1,-exp(-1/2)/2) = 1.7564312086261696769827376166... - Vaclav Kotesovec, Jul 05 2021