E.g.f.: exp( exp(exp(x) - 1) - exp(x) ).

Terms

a(0) =1a(1) =0a(2) =1a(3) =4a(4) =17a(5) =91a(6) =587a(7) =4327a(8) =35604a(9) =323316a(10) =3210600a(11) =34574453a(12) =400893066a(13) =4975247460a(14) =65755573847a(15) =921535225267