3764767domain: NPropertiesPrimalityPrimeyesAppears in sequencesPrimes of the form 2^r*7^s - 1.at n=22A077314Primes of the form 4*k^3 - 1.at n=18A199367Numbers x such that it is possible to find a value k for which Sum_{j=1..x} (x mod j) = Sum_{j=1..k} j.at n=21A244409Prime numbersat n=267668