52495396602
domain: N
Appears in sequences
- Primary pseudoperfect numbers: numbers n > 1 such that 1/n + sum 1/p = 1, where the sum is over the primes p | n.at n=6A054377
- Composite numbers m such that (m'+1)' = m', where m' = A003415(m) is the arithmetic derivative of m.at n=13A185222
- Numbers m such that (m'+1)' = m-1, where m' is the arithmetic derivative of m.at n=17A203618
- 1-Sondow numbers: numbers j such that p divides j/p + 1 for every prime divisor p of j.at n=7A349193