[ exp(12/19)*n! ].

Terms

a(0) =1a(1) =3a(2) =11a(3) =45a(4) =225a(5) =1354a(6) =9478a(7) =75824a(8) =682423a(9) =6824239a(10) =75066638a(11) =900799664a(12) =11710395639a(13) =163945538959