[ exp(9/14)*n! ].

Terms

a(0) =1a(1) =3a(2) =11a(3) =45a(4) =228a(5) =1369a(6) =9585a(7) =76684a(8) =690164a(9) =6901640a(10) =75918047a(11) =911016565a(12) =11843215346a(13) =165805014854