[ exp(4/11)*n! ].

Terms

a(0) =1a(1) =2a(2) =8a(3) =34a(4) =172a(5) =1035a(6) =7250a(7) =58002a(8) =522021a(9) =5220213a(10) =57422352a(11) =689068235a(12) =8957887058a(13) =125410418819