Expansion of e.g.f.: 1/(1 - x*(1+x)^x).

Terms

a(0) =1a(1) =1a(2) =2a(3) =12a(4) =60a(5) =460a(6) =3900a(7) =39438a(8) =456288a(9) =5896224a(10) =85230000a(11) =1349017560a(12) =23353941600a(13) =437432418696