210601domain: NPropertiesPrimalityPrimeyesAppears in sequencesNumber of n X 3 0..2 arrays with horizontal differences mod 3 never 1, vertical differences mod 3 never -1, and rows and columns lexicographically nondecreasing.at n=19A229440List of primes p for which p^n - 2 is prime for n = 1, 3, and 5.at n=18A242517Prime numbersat n=18861