a(n) = (1/4)*(binomial(4*n, 2*n) - (-1)^n*binomial(2*n, n) + (1-(-1)^n)*binomial(2*n, n)^2).
A037976
a(n) = (1/4)*(binomial(4*n, 2*n) - (-1)^n*binomial(2*n, n) + (1-(-1)^n)*binomial(2*n, n)^2).
Terms
- a(0) =0a(1) =4a(2) =16a(3) =436a(4) =3200a(5) =78004a(6) =675808a(7) =15919320a(8) =150266880a(9) =3450748180a(10) =34461586016a(11) =774842070600
External references
- oeis: A037976