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

Terms

a(0) =1a(1) =1a(2) =2a(3) =9a(4) =48a(5) =315a(6) =2520a(7) =23415a(8) =248640a(9) =2972025a(10) =39463200a(11) =576413145a(12) =9184855680a(13) =158550787395