Floor(exp(n)/n^2).

Terms

a(0) =2a(1) =1a(2) =2a(3) =3a(4) =5a(5) =11a(6) =22a(7) =46a(8) =100a(9) =220a(10) =494a(11) =1130a(12) =2617a(13) =6135a(14) =14528a(15) =34711a(16) =83581a(17) =202654a(18) =494410a(19) =1212912a(20) =2990511a(21) =7406844a(22) =18421178a(23) =45988059a(24) =115207838a(25) =289540842a(26) =729832977a(27) =1844715643a(28) =4674594883a(29) =11873860646