139589domain: NPropertiesPrimalityPrimeyesAppears in sequencesPrimes p such that p+2, p*(p+1)/2-2 and p*(p+1)/2+2 are also primes.at n=31A349336Least number that reaches 1 after exactly n iterations of the infinitary analog of the totient function A384247.at n=22A385747Prime numbersat n=12973