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

Terms

a(0) =1a(1) =1a(2) =2a(3) =7a(4) =33a(5) =191a(6) =1323a(7) =10711a(8) =99151a(9) =1032385a(10) =11943003a(11) =151979213a(12) =2109829857a(13) =31730171539a(14) =513903517585