%I #4 May 31 2017 21:23:58

%S 3,5,10,16,18,24,27,29,33,38,44,47,52,55,57,62,65,70,76,79,84,87,89,

%T 94,99,101,106,112,114,120,123,125,130,136,139,141,145,150,156,159,

%U 164,167,169,174,179,181,186,192,196,199,201,206,211,213,218,224,226

%N Positions of 1 in A287561.

%C a(n) - a(n-1) is in {1,2,3,4,5,6} for n >= 1; also, 4n - a(n) is in {0,1,2,3} for n >= 1. The first 20 numbers 4n - a(n) are 1, 3, 2, 0, 2, 0, 1, 3, 3, 2, 0, 1, 0, 1, 3, 2, 3, 2, 0, 1, with

%C 0 in positions given by A287565,

%C 1 in positions given by A287562,

%C 2 in positions given by A287563,

%C 3 in positions given by A287564.

%H Clark Kimberling, <a href="/A287563/b287563.txt">Table of n, a(n) for n = 1..10000</a>

%t s = Nest[Flatten[# /. {0 -> {0, 2, 1, 3}, 1 -> {2, 1, 3, 0}, 2 -> {1, 3, 0, 2}, 3 -> {3, 0, 2, 1}}] &, {0}, 9]; (* A287561 *)

%t Flatten[Position[s, 0]]; (* A287562 *)

%t Flatten[Position[s, 1]]; (* A287563 *)

%t Flatten[Position[s, 2]]; (* A287564 *)

%t Flatten[Position[s, 3]]; (* A287565 *)

%Y Cf. A287561, A287562, A287564, A287565.

%K nonn,easy

%O 1,1

%A _Clark Kimberling_, May 31 2017