699134domain: NAppears in sequencesa(n) is the number k such that 2^(2k+1)-1 = A000668(n+1).at n=33A146768Decimal representation of the x-axis, from the origin to the right edge, of the n-th stage of growth of the two-dimensional cellular automaton defined by "Rule 841", based on the 5-celled von Neumann neighborhood.at n=20A284246