783421domain: NPropertiesPrimalityPrimeyesAppears in sequencesn-th occurrence of gap of n between primes occurs at prime a(n), n even, n >= 2.at n=25A054587Number of active (ON, black) cells at stage 2^n-1 of the two-dimensional cellular automaton defined by "Rule 595", based on the 5-celled von Neumann neighborhood.at n=9A273141Prime numbersat n=62722