207553
domain: N
Appears in sequences
- Numbers m such that DivisorSigma(4*k-2, m) mod m = 0 holds presumably for all k; that is, (4k-2)-power-sums of divisors of m are divisible by m for all k.at n=23A066290
- For every positive integer m, let u(m) = (d(1),d(2),...,d(k)) be the unitary divisors of m. The sequence (a(n)) consists of successive numbers m which d(k)/d(1) + d(k-1)/d(2) + ... + d(k)/d(1) is an integer.at n=25A229996
- Numbers that divide the average of the sum of the squares of their divisors.at n=11A255244
- Numbers such that A017666(n) = A017668(n).at n=9A261989
- Numbers k such that the sum of the squares of the odd divisors of k (A050999) is divisible by k.at n=37A355543