[ exp(4/17)*n! ].

Terms

a(0) =1a(1) =2a(2) =7a(3) =30a(4) =151a(5) =911a(6) =6377a(7) =51016a(8) =459145a(9) =4591451a(10) =50505962a(11) =606071554a(12) =7878930204a(13) =110305022865