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

A036910

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

Terms

    a(0) =1a(1) =5a(2) =53a(3) =662a(4) =8885a(5) =124130a(6) =1778966a(7) =25947612a(8) =383358645a(9) =5719519850a(10) =85990654178

External references