[ exp(5/22)*n! ].

Terms

a(0) =1a(1) =2a(2) =7a(3) =30a(4) =150a(5) =903a(6) =6326a(7) =50608a(8) =455476a(9) =4554768a(10) =50102455a(11) =601229463a(12) =7815983029a(13) =109423762408