Euler numbers written backwards.

Terms

a(0) =1a(1) =1a(2) =1a(3) =2a(4) =5a(5) =61a(6) =16a(7) =272a(8) =5831a(9) =6397a(10) =12505a(11) =297353a(12) =5672072a(13) =65286322a(14) =189063991a(15) =2137573091a(16) =54121519391a(17) =679243568902