8184977domain: NPropertiesPrimalityPrimeyesAppears in sequencesPrime values of n for which n*2^k + 1 is composite for all positive integers k.at n=16A137715Odd integers n such that for every integer k>0, n*2^k+1 has a divisor in the set { 3, 5, 7, 13, 19, 37, 73 }.at n=6A244562Prime numbersat n=551384