O.g.f. satisfies A^4(z) = 1/(1 - z)*( BINOMIAL(BINOMIAL(A(z))) )^3.

A258379

O.g.f. satisfies A^4(z) = 1/(1 - z)*( BINOMIAL(BINOMIAL(A(z))) )^3.

Terms

    a(0) =1a(1) =7a(2) =73a(3) =1071a(4) =21249a(5) =549927a(6) =17907177a(7) =709326255a(8) =33202983873

External references