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Positions of 3 in A287576.
6

%I #4 Jun 01 2017 21:09:40

%S 2,7,12,13,17,22,27,32,36,37,42,47,51,56,57,62,67,72,73,78,82,87,92,

%T 93,97,102,107,112,116,117,122,127,132,133,138,143,147,152,153,158,

%U 162,167,172,173,177,182,187,192,193,198,203,208,212,213,218,223,227

%N Positions of 3 in A287576.

%C a(n) - a(n-1) is in {1,4,5} for n >= 1; also, 4n - a(n) is in {0,1,2,3} for n >= 1. The first 20 numbers 4n - a(n) are 2, 1, 0, 3, 3, 2, 1, 0, 0, 3, 2, 1, 1, 0, 3, 2, 1, 0, 3, 2, with

%C 0 in positions given by A287579,

%C 1 in positions given by A287580,

%C 2 in positions given by A287577,

%C 3 in positions given by A287578.

%H Clark Kimberling, <a href="/A287580/b287580.txt">Table of n, a(n) for n = 1..10000</a>

%F a(n) = 4n - A287576(n) for n >= 1.

%t s = Nest[Flatten[# /. {0 -> {0,3,2,1}, 1 -> {3,2,1,0}, 2 -> {2,1,0,3}, 3 -> {1,0,3,2}}] &, {0}, 9]; (* A287576 *)

%t Flatten[Position[s, 0]]; (* A287577 *)

%t Flatten[Position[s, 1]]; (* A287578 *)

%t Flatten[Position[s, 2]]; (* A287579 *)

%t Flatten[Position[s, 3]]; (* A287580 *)

%Y Cf. A287576, A287577, A287578, A287579.

%K nonn,easy

%O 1,1

%A _Clark Kimberling_, Jun 01 2017