-667

Appears in sequences

• The bottom entry in the difference table of the divisors of n.at n=59A187202
• First differences of number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 209", based on the 5-celled von Neumann neighborhood.at n=19A270894
• Triangle T(n,k) read by rows, giving even-numbered coefficients of the matching polynomial of the n-ladder graph.at n=30A308244