119279

Appears in sequences

• Numbers k such that sum of proper divisors or aliquot parts of k^2 (excluding 1) is a square, or A048050(k^2) is a square.at n=6A063900
• Integers m such that phi(sigma(k))/sigma(phi(k)) > phi(sigma(m))/sigma(phi(m)) for all k<m.at n=18A227011
• Numbers n such that sum of the proper divisors of n is the square of the sum of the digits of n.at n=17A279459
• a(n) = Sum_{1 <= x_1 <= x_2 <= x_3 <= x_4 <= x_5 <= n} gcd(x_1, x_2, x_3 , x_4, x_5, n).at n=24A343519