E.g.f. exp(-x)*exp(exp(2*x)/2-1/2)/2 + 1/2.

Terms

a(0) =1a(1) =0a(2) =1a(3) =2a(4) =10a(5) =48a(6) =276a(7) =1768a(8) =12552a(9) =97408a(10) =818704a(11) =7396384a(12) =71380640a(13) =732058880a(14) =7943068992a(15) =90833753728