[ exp(3/16)*n! ].

Terms

a(0) =1a(1) =2a(2) =7a(3) =28a(4) =144a(5) =868a(6) =6079a(7) =48635a(8) =437716a(9) =4377168a(10) =48148851a(11) =577786219a(12) =7511220852a(13) =105157091938