A118790 Secondary diagonal of triangle A118788.

1, 3, 23, 255, 3679, 65247, 1371887, 33347535, 919848991, 28382683263, 968565339983, 36217270235055, 1472548026160639, 64679673007670367, 3052084360057720367, 153980839859926277775, 8270901171633696369631

Offset

0,2

Links

Vaclav Kotesovec, Table of n, a(n) for n = 0..200

Formula

a(n) = (n+1)!*[x^n] ( x/(2*x + log(1-x)) )^(n+2).

a(n) ~ n^(n+1) / (4 * exp(n) * (1 - log(2))^(n + 3/2)). - Vaclav Kotesovec, Sep 01 2025

Mathematica

Table[(n+1)! * SeriesCoefficient[(x/(2*x + Log[1-x]))^(n+2), {x, 0, n}], {n, 0, 20}] (* Vaclav Kotesovec, Sep 01 2025 *)

Prog

(PARI)
{a(n)=local(x=X+X^2*O(X^(n))); (n+1)!*polcoeff((x/(2*x+log(1-x)))^(n+2), n, X)}

Crossrefs

Cf. A118788, A118789.

Sequence in context: A199750 A318004 A098681 * A159017 A385413 A004700

Adjacent sequences: A118787 A118788 A118789 * A118791 A118792 A118793

Keyword

nonn

Author

Paul D. Hanna, Apr 29 2006

Status

approved