[ exp(13/14)*n! ].

Terms

a(0) =2a(1) =5a(2) =15a(3) =60a(4) =303a(5) =1822a(6) =12755a(7) =102045a(8) =918409a(9) =9184097a(10) =101025071a(11) =1212300855a(12) =15759911118a(13) =220638755664