A287441 - OEIS

%I #4 May 29 2017 23:58:19

%S 3,5,7,11,13,18,19,23,27,29,31,36,37,41,45,48,50,52,55,59,63,65,67,72,

%T 75,77,79,83,85,90,91,95,99,102,104,106,109,113,117,119,121,126,129,

%U 131,133,138,140,142,146,148,153,154,158,162,163,167,171,173,175

%N Positions of 2 in A287438.

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

%H Clark Kimberling, <a href="/A287441/b287441.txt">Table of n, a(n) for n = 1..10000</a>

%F a(n) + A287438(n) = 3n.

%t s = Nest[Flatten[# /. {0->{0, 1, 2}, 1->{1, 2, 0}, 2->{2, 1, 0}}] &, {0}, 9]; (*A287438*)

%t Flatten[Position[s, 0]]; (*A189728*)

%t Flatten[Position[s, 1]]; (*A189670*)

%t Flatten[Position[s, 2]]; (*A287441*)

%Y Cf. A287438, A189728, A189670.

%K nonn,easy

%O 1,1

%A _Clark Kimberling_, May 26 2017