A217485 Convolution of the numbers in sequence A080253.

1, 6, 43, 396, 4565, 64146, 1073919, 20996376, 471081385, 11947911966, 338204687315, 10570101018276, 361458024882045, 13421571912745386, 537661560385125031, 23108777539028187696, 1060571767117824260945, 51760585513634983767606

Offset

0,2

Links

Table of n, a(n) for n=0..17.

Formula

a(n) = sum(c(k)*c(n.k),k=0..n), where c(n) = A080253(n).

a(n) ~ n! * 2^(n + 1/2) / (log(2))^(n+1). - Vaclav Kotesovec, Nov 27 2017

Mathematica

t[n_] := Sum[StirlingS2[n, k] k!, {k, 0, n}]; c[n_] := Sum[Binomial[n, k] 2^k t[k], {k, 0, n}]; Table[Sum[c[k]c[n-k], {k, 0, n}], {n, 0, 100}]

Prog

(Maxima) t(n):=sum(stirling2(n, k)*k!, k, 0, n);
c(n):=sum(binomial(n, k)*2^k*t(k), k, 0, n);
makelist(sum(c(k)*c(n-k), k, 0, n), n, 0, 40);

Crossrefs

Cf. A080253, A000670, A217483, A217484, A217486, A217487, A217488.

Sequence in context: A090010 A176732 A062266 * A337555 A290783 A159604

Adjacent sequences: A217482 A217483 A217484 * A217486 A217487 A217488

Keyword

nonn

Author

Emanuele Munarini, Oct 04 2012

Status

approved