This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A287182 #12 Jul 31 2025 06:59:43
%S A287182 7,17,21,23,30,40,50,54,56,63,67,69,73,75,82,92,96,98,105,115,125,129,
%T A287182 131,138,148,158,162,164,171,175,177,181,183,190,200,204,206,213,217,
%U A287182 219,223,225,232,236,238,242,244,251,261,265,267,274,284,294,298
%N A287182 Positions of 2 in A287179.
%H A287182 Clark Kimberling, <a href="/A287182/b287182.txt">Table of n, a(n) for n = 1..10000</a> (terms 7754 ff. corrected by _Georg Fischer_, Jun 04 2020)
%t A287182 s = Nest[Flatten[# /. {0 -> {1, 0}, 1 -> {2, 0}, 2 -> 1}] &, {0}, 9] (* A287179 *)
%t A287182 Flatten[Position[s, 0]] (* A287180 *)
%t A287182 Flatten[Position[s, 1]] (* A287181 *)
%t A287182 Flatten[Position[s, 2]] (* A287182 *)
%Y A287182 Cf. A287179, A287180, A287181.
%K A287182 nonn,easy
%O A287182 1,1
%A A287182 _Clark Kimberling_, May 23 2017