a(n) = (binomial(4*n, 2*n) + (-1)^n*binomial(2*n, n)^2)/2.

A036911

a(n) = (binomial(4*n, 2*n) + (-1)^n*binomial(2*n, n)^2)/2.

Terms

    a(0) =1a(1) =1a(2) =53a(3) =262a(4) =8885a(5) =60626a(6) =1778966a(7) =14168988a(8) =383358645a(9) =3355615450a(10) =85990654178a(11) =803232328548

External references