[ exp(5/19)*n! ].

Terms

a(0) =1a(1) =2a(2) =7a(3) =31a(4) =156a(5) =936a(6) =6557a(7) =52457a(8) =472118a(9) =4721185a(10) =51933039a(11) =623196471a(12) =8101554127a(13) =113421757790