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Positions of 0 in A287385.
4

%I #4 May 25 2017 13:14:58

%S 1,6,7,10,15,16,19,22,27,28,31,36,37,42,43,46,51,52,55,60,61,64,67,72,

%T 73,78,79,82,87,88,91,94,99,100,105,106,109,112,117,118,123,124,127,

%U 132,133,136,141,142,145,150,151,154,157,162,163,168,169,172,177

%N Positions of 0 in A287385.

%C a(n) - a(n-1) is in {1,3,5} for n >= 1; also, 3n - a(n) is in {0,2} for n >= 1. The first 20 numbers 3n - a(n) are 2, 0, 2, 2, 0, 2, 2, 2, 0, 2, 2, 0, 2, 0, 2, 2, 0, 2, 2, 0, with 0 in positions given by A287387.

%H Clark Kimberling, <a href="/A287386/b287386.txt">Table of n, a(n) for n = 1..10000</a>

%t s = Nest[Flatten[# /. {0->{0, 1, 2}, 1->{2, 1, 0}, 2->{0, 2, 1}}] &, {0}, 9]; (*A287385*)

%t Flatten[Position[s, 0]]; (*A287386*)

%t Flatten[Position[s, 1]]; (*A287387*)

%t Flatten[Position[s, 2]]; (*A287388*)

%Y Cf. A287385, A287387, A287388.

%K nonn,easy

%O 1,2

%A _Clark Kimberling_, May 25 2017