549753192448
domain: N
Appears in sequences
- Numbers k such that sigma(k) == 4 (mod k).at n=15A045769
- Numbers k such that sigma(k) == 0 (mod k+2).at n=13A067702
- Numbers k whose abundance is 4: sigma(k) - 2*k = 4.at n=12A088832
- (N\{4})-perfect numbers, i.e., numbers m for which sigma(m)-4 = 2m, if 4|m, otherwise sigma(m) = 2m.at n=9A181597
- Numbers m=2^(t-1)*(2^t-5), where 2^t-5 is prime.at n=7A181704