72565

Appears in sequences

• Numbers k such that k and k^2 use only the digits 2, 5, 6, 7 and 9.at n=26A137112
• a(n) = Sum_{1 <= x_1, x_2, x_3 <= n} gcd(x_1, n)/gcd(x_1, x_2, x_3, n).at n=27A373060