G.f.: Sum_{n>=0} [Sum_{k>=0} C(n+k-1,k)^2*x^k]^n * x^n.

A183165

G.f.: Sum_{n>=0} [Sum_{k>=0} C(n+k-1,k)^2*x^k]^n * x^n.

Terms

    a(0) =1a(1) =1a(2) =2a(3) =10a(4) =63a(5) =521a(6) =5295a(7) =64048a(8) =907199a(9) =14717173a(10) =270429934a(11) =5561319631a(12) =126824201866

External references