Floor(exp(n)/n^3).

Terms

a(0) =2a(1) =0a(2) =0a(3) =0a(4) =1a(5) =1a(6) =3a(7) =5a(8) =11a(9) =22a(10) =44a(11) =94a(12) =201a(13) =438a(14) =968a(15) =2169a(16) =4916a(17) =11258a(18) =26021a(19) =60645a(20) =142405a(21) =336674a(22) =800920a(23) =1916169a(24) =4608313a(25) =11136186a(26) =27030851a(27) =65882701a(28) =161192927a(29) =395795354