[ exp(1/14)*n! ].

Terms

a(0) =1a(1) =2a(2) =6a(3) =25a(4) =128a(5) =773a(6) =5413a(7) =43305a(8) =389748a(9) =3897481a(10) =42872296a(11) =514467563a(12) =6688078329a(13) =93633096607