%I #12 Nov 14 2023 09:17:12
%S 0,0,2,0,0,4,4,0,0,2,2,0,0,8,8,0,0,2,2,0,0,4,4,0,0,2,2,0,0,16,16,0,0,
%T 2,2,0,0,4,4,0,0,2,2,0,0,8,8,0,0,2,2,0,0,4,4,0,0,2,2,0,0,32,32,0,0,2,
%U 2,0,0,4,4,0,0,2,2,0,0,8,8,0,0,2,2,0,0,4,4,0,0,2,2
%N Number of iterations until a repeating cycle begins in rule 161 cellular automaton in a cyclic universe of circumference n starting with one cell on.
%e For n = 2 we have: 10 -> 01 -> 10; since the cycle started from the 0th iteration, a(2) = 0.
%e For n = 3 we have: 100 -> 000 -> 111 -> 111; since the cycle started from the 2nd iteration, a(3) = 2.
%Y Cf. A334506, A000029.
%K nonn
%O 1,3
%A _Angelo Rosso_, Nov 03 2023