A294251 E.g.f.: exp((1+x)*(1+x^2)*(1+x^3) - 1).

1, 1, 3, 19, 97, 681, 5971, 50443, 512289, 5821777, 67968451, 880345731, 12230425153, 177123301369, 2759869352787, 45321758937211, 776008738668481, 14020831026652833, 264488668445049859, 5187662544182915827, 106241960755765408161, 2257485400533886011721

Offset: 0

Author

Seiichi Manyama, Oct 26 2017

Keywords

• nonn

Links

• Seiichi Manyama, Table of n, a(n) for n = 0..484

Crossrefs

Column k=3 of A294250.

Cf. A294214, A294291.

Programs

PARI

N=66; x='x+O('x^N); Vec(serlaplace(exp((1+x)*(1+x^2)*(1+x^3)-1)))

Formula

a(n) = a(n-1) + 2*(n-1)*a(n-2) + 6*(n-2)*(n-1)*a(n-3) + 4*(n-3)*(n-2)*(n-1)*a(n-4) + 5*(n-4)*(n-3)*(n-2)*(n-1)*a(n-5) + 6*(n-5)*(n-4)*(n-3)*(n-2)*(n-1)*a(n-6). - Vaclav Kotesovec, Dec 02 2021