E.g.f.: exp(x + 4*x^2 + 9*x^3).

Terms

a(0) =1a(1) =1a(2) =9a(3) =79a(4) =457a(5) =5901a(6) =66841a(7) =720259a(8) =11155089a(9) =158315257a(10) =2361665161a(11) =42133751991a(12) =720156599449