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%I #4 May 25 2017 13:14:44
%S 4,6,10,14,18,22,26,32,34,38,42,48,50,54,60,62,66,70,74,80,82,86,92,
%T 94,98,102,106,112,116,118,122,126,130,134,138,144,146,150,156,158,
%U 162,166,170,176,180,182,186,190,194,198,202,208,210,214,220,222,228
%N Positions of 2 in A101666.
%C 4n - a(n) is in {0,2} for n >= 1. The first 20 numbers 4n - a(n) are 0, 2, 2, 2, 2, 2, 2, 0, 2, 2, 2, 0, 2, 2, 0, 2, 2, 2, 2, 0.
%H Clark Kimberling, <a href="/A287375/b287375.txt">Table of n, a(n) for n = 1..10000</a>
%F a(n) = 2*A287374(n) for n >= 1.
%t s = Nest[Flatten[# /. {0 -> {0, 1}, 1 -> {1, 2}, 2 -> {1,0}}] &, {0}, 12] (* A101666 *)
%t Flatten[Position[s, 0]] (* A287373 *)
%t Flatten[Position[s, 1]] (* A287374 *)
%t Flatten[Position[s, 2]] (* A287375 *)
%Y Cf. A287372, A287373, A287374.
%K nonn,easy
%O 1,1
%A _Clark Kimberling_, May 25 2017