A113663 Self-convolution cube of A113669, where a(n) = A113669(n+1)/(n+1).

1, 3, 21, 226, 3216, 56229, 1158249, 27367560, 728245038, 21531918486, 700096811670, 24826071871890, 953594302010230, 39446976470619801, 1748616265593936681, 82701936091459565976, 4157268410857737364182

Offset: 0

Author

Paul D. Hanna, Nov 04 2005

Keywords

• nonn

Links

• Vaclav Kotesovec, Table of n, a(n) for n = 0..350

Crossrefs

Cf. A113669, A113662, A113664, A113665, A113666, A113667, A113668.

Programs

PARI

{a(n)=local(A=1+x*O(x^n));for(i=1,n, A=(1+x*deriv(x*A))^3);polcoeff(A,n,x)}

Formula

G.f. satisfies: A(x) = (1 + x*d/dx[x*A(x)] )^3.

a(n) ~ c * 3^n * n! * n^(2/3), where c = 0.7528584991179137287053869... - Vaclav Kotesovec, Oct 23 2020