G.f.: 1 = Sum_{n>=0} a(n) * x^n * Sum_{k=0..n} C(n,k)^3 * (-x)^k.

A247032

G.f.: 1 = Sum_{n>=0} a(n) * x^n * Sum_{k=0..n} C(n,k)^3 * (-x)^k.

Terms

    a(0) =1a(1) =1a(2) =8a(3) =215a(4) =13544a(5) =1646568a(6) =342128448a(7) =111806434449

External references