A Jacobsthal Fibonacci product: a(n) = (2^n + 2*(-1)^n)*Fibonacci(n-1)/3.

Terms

a(0) =1a(1) =0a(2) =2a(3) =2a(4) =12a(5) =30a(6) =110a(7) =336a(8) =1118a(9) =3570a(10) =11628a(11) =37510a(12) =121574a(13) =393120a(14) =1272646a(15) =4117594a(16) =13326060a(17) =43122030a(18) =139549054a(19) =451585008a(20) =1461368206a(21) =4729073250a(22) =15303624492a(23) =49523533622a(24) =160261578742a(25) =518617270080