a(n) = 2*sum(C(n,2k+1)*F(2k), k=0..floor((n-1)/2)), where F(n) are Fibonacci numbers A000045.

A097040

a(n) = 2*sum(C(n,2k+1)*F(2k), k=0..floor((n-1)/2)), where F(n) are Fibonacci numbers A000045.

Terms

    a(0) =0a(1) =0a(2) =2a(3) =8a(4) =26a(5) =76a(6) =212a(7) =576a(8) =1542a(9) =4092a(10) =10802a(11) =28424a(12) =74648a(13) =195808a(14) =513242a(15) =1344672a(16) =3521994a(17) =9223284a(18) =24151052a(19) =63235040a(20) =165562430a(21) =433465780a(22) =1134856802a(23) =2971140048a(24) =7778620656a(25) =20364814656a(26) =53315973362a(27) =139583348216

External references