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

A079489

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

Terms

    a(0) =1a(1) =3a(2) =22a(3) =211a(4) =2306a(5) =27230a(6) =338444a(7) =4362627a(8) =57788170a(9) =781825066a(10) =10757497972a(11) =150073096238

External references