[ exp(7/11)*n! ].

Terms

a(0) =1a(1) =3a(2) =11a(3) =45a(4) =226a(5) =1360a(6) =9523a(7) =76188a(8) =685696a(9) =6856969a(10) =75426669a(11) =905120038a(12) =11766560499a(13) =164731846995