33660501840domain: NAppears in sequencesa(n) = (12*n)!*(3*n)!/((6*n)!*(5*n)!*(4*n)!).at n=3A295435a(n) = (6*n)!/((3*n)!*(2*n)!) * (3*n/2)!/(5*n/2)!.at n=6A347857