Expansion of Sum_{k>=0} (x * (1 + (k * x)^3))^k.

Terms

a(0) =1a(1) =1a(2) =1a(3) =1a(4) =2a(5) =17a(6) =82a(7) =257a(8) =690a(9) =3484a(10) =26978a(11) =160347a(12) =726085a(13) =3529206a(14) =26885924a(15) =220706533a(16) =1474182023a(17) =8834370165a(18) =65392181686a(19) =604821608674