G.f.: 1 = Sum_{n>=0} a(n)*x^n * [ Sum_{k=0..n+1} binomial(n+1, k)^3 * (-x)^k ]^3.
A247031
G.f.: 1 = Sum_{n>=0} a(n)*x^n * [ Sum_{k=0..n+1} binomial(n+1, k)^3 * (-x)^k ]^3.
Terms
- a(0) =1a(1) =3a(2) =69a(3) =5005a(4) =806148a(5) =239220375a(6) =116532061510
External references
- oeis: A247031