a(n) = floor(e^(n+1) - e^n) - Fibonacci(n).

Terms

a(0) =1a(1) =3a(2) =11a(3) =32a(4) =90a(5) =250a(6) =685a(7) =1871a(8) =5101a(9) =13889a(10) =37792a(11) =102791a(12) =279514a(13) =759957a(14) =2066036a(15) =5616483a(16) =15267855a(17) =41503419a(18) =112819747a(19) =306678713a(20) =833643774a(21) =2266086165a(22) =6159872889a(23) =16744290026a(24) =45515730839a(25) =123724635066a(26) =336318509779a(27) =914208627271