[ exp(12/13)*n! ].

Terms

a(0) =2a(1) =5a(2) =15a(3) =60a(4) =302a(5) =1812a(6) =12685a(7) =101486a(8) =913377a(9) =9133773a(10) =100471510a(11) =1205658127a(12) =15673555658a(13) =219429779214