Expansion of e.g.f. exp(x * (1+x)^2).

Terms

a(0) =1a(1) =1a(2) =5a(3) =19a(4) =97a(5) =581a(6) =3661a(7) =26335a(8) =202049a(9) =1659817a(10) =14621941a(11) =135567851a(12) =1326672865a(13) =13624218349a(14) =146056961597