a(n) = Fibonacci(n-2) + 2*a(n-2) - (n mod 2).

Terms

a(0) =0a(1) =0a(2) =0a(3) =0a(4) =1a(5) =1a(6) =5a(7) =6a(8) =18a(9) =24a(10) =57a(11) =81a(12) =169a(13) =250a(14) =482a(15) =732a(16) =1341a(17) =2073a(18) =3669a(19) =5742a(20) =9922a(21) =15664a(22) =26609a(23) =42273a(24) =70929a(25) =113202a(26) =188226a(27) =301428a(28) =497845a(29) =799273