1048252domain: NAppears in sequencesa(n) = 2^(n+1) - (n-1)^2.at n=19A243860Decimal representation of the x-axis, from the left edge to the origin, of the n-th stage of growth of the two-dimensional cellular automaton defined by "Rule 377", based on the 5-celled von Neumann neighborhood.at n=19A281630