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

Terms

a(0) =1a(1) =0a(2) =0a(3) =3a(4) =0a(5) =15a(6) =90a(7) =105a(8) =2520a(9) =8505a(10) =66150a(11) =634095a(12) =3118500a(13) =40675635a(14) =285675390a(15) =2896618725a(16) =31556725200a(17) =281774718225