a(n) = A322242(n)^2, the square of the central coefficient in (1 + 3*x + 4x^2)^n.

A322243

a(n) = A322242(n)^2, the square of the central coefficient in (1 + 3*x + 4x^2)^n.

Terms

    a(0) =1a(1) =9a(2) =289a(3) =9801a(4) =370881a(5) =14768649a(6) =609546721a(7) =25795893321

External references