-2689

Appears in sequences

• The real part of complex sequence: a(n) = a(n-1) + (1+i)*a(n-2).at n=16A143055
• First differences of number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 145", based on the 5-celled von Neumann neighborhood.at n=27A270289