a(n) = n*F(n) + (n-1)*F(n-1).

Terms

a(0) =1a(1) =3a(2) =8a(3) =18a(4) =37a(5) =73a(6) =139a(7) =259a(8) =474a(9) =856a(10) =1529a(11) =2707a(12) =4757a(13) =8307a(14) =14428a(15) =24942a(16) =42941a(17) =73661a(18) =125951a(19) =214739a(20) =365166a(21) =619508a(22) =1048753a(23) =1771943a(24) =2988457a(25) =5031843a(26) =8459504a(27) =14201994a(28) =23811349a(29) =39873841