a(n) = binomial(6*n, n) * hypergeom([-5*n, -n], [-6*n], -1).

A341491

a(n) = binomial(6*n, n) * hypergeom([-5*n, -n], [-6*n], -1).

Terms

    a(0) =1a(1) =11a(2) =221a(3) =4991a(4) =118721a(5) =2908411a(6) =72616013a(7) =1837271615a(8) =46943003137

External references