18116083216domain: NAppears in sequencesSquare array read by ascending antidiagonals: T(n,k) = (2*k)!/k!^2 * ( (2*n*k)! * ((n + 2)*k)! )/( (n*k)! * ((n + 1)*k)!^2 ) for n, k > = 0.at n=42A364509a(n) = binomial(4*n, n)^2.at n=6A364510