[ exp(14/15)*n! ].

Terms

a(0) =2a(1) =5a(2) =15a(3) =61a(4) =305a(5) =1830a(6) =12816a(7) =102532a(8) =922793a(9) =9227935a(10) =101507290a(11) =1218087483a(12) =15835137282a(13) =221691921954