453024

Appears in sequences

• a(n) = Catalan(n)^2*(4n + 2).at n=6A267981
• Square array read by ascending antidiagonals: T(n,k) = (2*k)!/k! * ( (2*n*k)! * ((2*n+1)*k)! )/( (n*k)!^2 * ((n+1)*k)!^2 ).at n=29A364506