A381601 G.f. A(x) satisfies A(x) = 1/(1 - x * A(x)^3 * A(x*A(x)^3)^3).

1, 1, 7, 79, 1134, 18953, 353134, 7154751, 155181240, 3565276582, 86122663681, 2175366732971, 57218428637862, 1562164759518688, 44156180231275177, 1289514761824080659, 38840440076269957435, 1204858168452465020445, 38445264045516464373511

Offset: 0

Author

Seiichi Manyama, Mar 01 2025

Keywords

• nonn

Crossrefs

Column k=1 of A381594.

Programs

PARI

a(n, k=1) = if(k==0, 0^n, k*sum(j=0, n, binomial(3*n+j+k, j)/(3*n+j+k)*a(n-j, 3*j)));

Formula

See A381594.