a(n) = Fibonacci(n+1)^3 - Fibonacci(n-1)^3.

Terms

a(0) =0a(1) =1a(2) =7a(3) =26a(4) =117a(5) =485a(6) =2072a(7) =8749a(8) =37107a(9) =157114a(10) =665665a(11) =2819609a(12) =11944368a(13) =50596649a(14) =214331663a(15) =907922170a(16) =3846022173a(17) =16292007901a(18) =69014058568a(19) =292348234421