a(n) = 2*a(n - 2) + a(n - 4) with a(0) = -1, a(1) = 1, a(2) = 3, a(3) = 5.

Terms

a(0) =-1a(1) =1a(2) =3a(3) =5a(4) =5a(5) =11a(6) =13a(7) =27a(8) =31a(9) =65a(10) =75a(11) =157a(12) =181a(13) =379a(14) =437a(15) =915a(16) =1055a(17) =2209a(18) =2547a(19) =5333a(20) =6149a(21) =12875a(22) =14845a(23) =31083a(24) =35839a(25) =75041a(26) =86523a(27) =181165a(28) =208885a(29) =437371