A357661 Expansion of e.g.f. cosh( (exp(2*x) - 1)/sqrt(2) ).

1, 0, 2, 12, 60, 320, 2040, 15568, 133648, 1230336, 11962400, 123144384, 1349008320, 15731096576, 194349866880, 2527082917120, 34392647418112, 488243791183872, 7216792525799936, 110936087161801728, 1771199461131500544, 29324602146652307456

Offset

0,3

Links

Table of n, a(n) for n=0..21.

Formula

a(n) = Sum_{k=0..floor(n/2)} 2^(n-k) * Stirling2(n,2*k).

Prog

(PARI) my(N=30, x='x+O('x^N)); apply(round, Vec(serlaplace(cosh((exp(2*x)-1)/sqrt(2)))))
(PARI) a(n) = sum(k=0, n\2, 2^(n-k)*stirling(n, 2*k, 2));

Crossrefs

Cf. A024430, A357662, A357663.

Cf. A009153, A264036, A357664.

Sequence in context: A001574 A074445 A038154 * A371399 A061834 A364283

Adjacent sequences: A357658 A357659 A357660 * A357662 A357663 A357664

Keyword

nonn

Author

Seiichi Manyama, Oct 07 2022

Status

approved