a(n) = 3 * h(n - 1) * h(n) for n >= 1, where h(n) = hypergeom([-n, -n], [1], 2), and a(0) = 1.

A358387

a(n) = 3 * h(n - 1) * h(n) for n >= 1, where h(n) = hypergeom([-n, -n], [1], 2), and a(0) = 1.

Terms

    a(0) =1a(1) =9a(2) =117a(3) =2457a(4) =60669a(5) =1620729a(6) =45385461a(7) =1311647913a(8) =38774378493

External references