502250domain: NAppears in sequencesNumbers k such that k and k^2 use only the digits 0, 2, 5 and 6.at n=47A136911Even numbers k such that the sum of divisors of k in Gaussian integers is a real number.at n=20A332532Expansion of Sum_{k>0} x^(2*k)/(1-x^k)^6.at n=34A363606