8513505domain: NAppears in sequencesa(n) = (2*n+1)*(3*n+1)*(4*n+1)*(5*n+1).at n=16A033592The (2^n)-th lucky number.at n=19A181383Triangle T(n, k) read by rows: T(n, k) = 2^n*binomial(2*n + 1, 2*k + 1) * Pochhammer(1/2, n - k) * Pochhammer(1/2, k).at n=30A380281