a(n) = the n-th order Taylor polynomial (centered at 0) of c(x)^(3*n) evaluated at x = 1, where c(x) = (1 - sqrt(1 - 4*x))/(2*x) is the o.g.f. of the sequence of Catalan numbers A000108.

A333095

a(n) = the n-th order Taylor polynomial (centered at 0) of c(x)^(3*n) evaluated at x = 1, where c(x) = (1 - sqrt(1 - 4*x))/(2*x) is the o.g.f. of the sequence of Catalan numbers A000108.

Terms

    a(0) =1a(1) =4a(2) =34a(3) =337a(4) =3554a(5) =38754a(6) =431521a(7) =4874377a(8) =55639010a(9) =640177033a(10) =7412165034a(11) =86256322816

External references