5308415domain: NAppears in sequencesLeast m which can be written as i*j+i+j in n different ways: A072670(m)=n.at n=42A072671Integers k such that there exists an integer 0<m<k such that sigma(m)^2 + sigma(k)^2 = 2*(m^2+k^2).at n=12A384255Odd numbers that are one less than the square of a perfect power.at n=31A389956