230567domain: NPropertiesPrimalityPrimeyesAppears in sequencesPrimes that remain prime through 3 iterations of function f(x) = 8x + 1.at n=24A023291Primes that remain prime through 4 iterations of function f(x) = 8x + 1.at n=2A023319Number of nontrivial prime powers p^k (k>1) less than 10^n.at n=12A267574Prime numbersat n=20489