[ exp(11/13)*n! ].

Terms

a(0) =2a(1) =4a(2) =13a(3) =55a(4) =279a(5) =1678a(6) =11746a(7) =93972a(8) =845751a(9) =8457518a(10) =93032708a(11) =1116392500a(12) =14513102503a(13) =203183435047