47901domain: NAppears in sequencesPartial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 931", based on the 5-celled von Neumann neighborhood.at n=32A273790a(n) = n! * [x^n] exp(x/(1 + n*x)).at n=5A318224