[ exp(11/20)*n! ].

Terms

a(0) =1a(1) =3a(2) =10a(3) =41a(4) =207a(5) =1247a(6) =8735a(7) =69884a(8) =628962a(9) =6289628a(10) =69185914a(11) =830230968a(12) =10793002593a(13) =151102036314