215264domain: NAppears in sequencesNumber of walks on square lattice.at n=27A005565a(n) = 841*n^2 - 2*n.at n=15A158401Numbers whose sum of proper square divisors is a palindrome in base 10 having at least two digits.at n=19A232892Numbers whose sum of square divisors is a palindrome in base 10 having at least two digits.at n=9A232893