788463617domain: NPropertiesPrimalityPrimeyesAppears in sequencesDenominator of the n-th convergent to Sum_{k>=0} 1/2^(2^k).at n=16A073415Number of active (ON, black) cells at stage 2^n-1 of the two-dimensional cellular automaton defined by "Rule 145", based on the 5-celled von Neumann neighborhood.at n=14A270287Prime numbersat n=40582924