G.f.: 1 = Sum_{n>=0} a(n) * x^n * (1 - (n+1)*x)^3.
A219779
G.f.: 1 = Sum_{n>=0} a(n) * x^n * (1 - (n+1)*x)^3.
Terms
- a(0) =1a(1) =3a(2) =15a(3) =100a(4) =819a(5) =7890a(6) =86995a(7) =1077150a(8) =14767575a(9) =221751010a(10) =3615510375a(11) =63552101550
External references
- oeis: A219779