Cubefree colossally superabundant numbers: cubefree numbers (A004709) k for which there is a positive exponent epsilon such that sigma(k)/k^{1 + epsilon} >= sigma(j)/j^{1 + epsilon} for all cubefree j > 1, so that k attains the maximum value of sigma(k)/k^{1 + epsilon} over the cubefree numbers.

A309875

Cubefree colossally superabundant numbers: cubefree numbers (A004709) k for which there is a positive exponent epsilon such that sigma(k)/k^{1 + epsilon} >= sigma(j)/j^{1 + epsilon} for all cubefree j > 1, so that k attains the maximum value of sigma(k)/k^{1 + epsilon} over the cubefree numbers.