G.f.: Sum_{n>=0} (n+1)*(n+2)/2 * x^n * (1+x)^(n*(n+2)).

A325586

G.f.: Sum_{n>=0} (n+1)*(n+2)/2 * x^n * (1+x)^(n*(n+2)).

Terms

    a(0) =1a(1) =3a(2) =15a(3) =67a(4) =336a(5) =1767a(6) =9873a(7) =58221a(8) =360930a(9) =2345469a(10) =15926115a(11) =112702725a(12) =829218143a(13) =6329731749a(14) =50032666719a(15) =408810685879

External references