225342

Appears in sequences

• Numbers k such that sigma(phi(sigma(k))) = sigma(k).at n=26A066471
• List of integers m>0 with m-1 and m+1 both prime, and m-2, m, m+2 all practical.at n=29A209236
• a(n) = sigma(n)*Lucas(n) where Lucas(n) = A000204(n) and sigma(n) = A000203(n) is the sum of divisors of n.at n=17A225528
• Expansion of 2/((1 - x)*(3 - theta_3(x))), where theta_3() is the Jacobi theta function.at n=34A303667