[ exp(13/20)*n! ].

Terms

a(0) =1a(1) =3a(2) =11a(3) =45a(4) =229a(5) =1379a(6) =9654a(7) =77234a(8) =695111a(9) =6951114a(10) =76462260a(11) =917547121a(12) =11928112585a(13) =166993576197