-2307

Appears in sequences

• First differences of number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 505", based on the 5-celled von Neumann neighborhood.at n=31A272584
• First differences of number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 507", based on the 5-celled von Neumann neighborhood.at n=31A272588
• Coefficients in the expansion of ([s] + [2s]x + [3s]x^2 + ...)/([r] + [2r]x + [3r]x^2 + ...); [ ] = floor, r = sqrt(3), s = sqrt(2).at n=28A279629
• a(n) = Sum_{k=1..n} (-1)^(k-1) * binomial(k+2,3) * floor(n/k).at n=29A366938