734449
domain: N
Appears in sequences
- Numbers whose sum of divisors is prime.at n=35A023194
- Least square s such that A078142(s) is equal to the n-th prime.at n=13A076830
- Squares of lesser of twin primes.at n=33A108570
- Odd numbers N for which numerator(sigma(N)/N) is a prime.at n=30A193065
- Composite numbers with both 10 and -10 as primitive root.at n=30A218766
- Nontrivial prime powers (A025475) which are a sum of a smaller nontrivial prime power and a perfect cube.at n=19A226232
- Numbers k such that tau(sigma(tau(k))) = sigma(tau(sigma(k))), where tau is A000005 and sigma is A000203.at n=24A237613
- Numbers n such that 2n-1 and sigma(n) are both primes.at n=19A249902
- Perfect powers m^k such that m, k and m+k are primes.at n=37A258400
- Odd numbers with prime sum of divisors.at n=28A278911
- a(n) is the smallest number k such that sigma(k) and sigma(k^n) are both primes.at n=10A299148
- Numbers m such that m! / sigma(m) is not an integer.at n=36A325436
- Numbers k for which A348717(k) is a multiple of A348717(sigma(k)).at n=41A364131