[ exp(17/20)*n! ].

Terms

a(0) =2a(1) =4a(2) =14a(3) =56a(4) =280a(5) =1684a(6) =11791a(7) =94334a(8) =849011a(9) =8490110a(10) =93391215a(11) =1120694585a(12) =14569029611a(13) =203966414562