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 A341257 #11 Aug 26 2021 23:34:41
%S A341257 1,2,3,6,7,9,12,14,15,21,24,30,31,35,41,45,48,52,58,62,63,75,81,93,96,
%T A341257 108,114,126,127,135,147,155,161,169,181,189,192,200,212,220,226,234,
%U A341257 246,254,255,279,291,315,321,345,357,381,384,408,420,444,450,474
%N A341257 Positions of palindromes in the ordering of all 01-words defined at A341256.
%C A341257 Also, the positions in A076478 of palindromes. - _Clark Kimberling_, Aug 16 2021
%e A341257 Among the first 20 words (0, 1, 00, 10, 01, 11, 000, 100, 010, 110, 001, 101, 011, 111, 0000, 1000, 0100, 1100, 0010, 1010), there are 9 palindromes: 0, 1, 00, 11, 000, 010, 101, 111, 0000, beginning in positions 1, 2, 3, 6, 7, 9, 12, 14, 15, respectively.
%t A341257 z = 800; s = Table[2 n - 1, {n, 1, z}];
%t A341257 t = Complement[Range[Max[s]], s];
%t A341257 s1[n_] := Length[Intersection[Range[n - 1], s]];
%t A341257 t1[n_] := n - 1 - s1[n];
%t A341257 w[1] = {0}; w[t[[1]]] = {1};
%t A341257 w[n_] := If[MemberQ[s, n], Join[{0}, w[s1[n]]], Join[{1}, w[t1[n]]]]
%t A341257 tt = Table[w[n], {n, 1, z}]; Select[tt, # == Reverse[#] &]
%t A341257 p = Select[Range[Length[tt]], tt[[#]] == Reverse[tt[[#]]] &]
%Y A341257 Cf. A341256.
%Y A341257 Appears to equal A044051 - 2. - _Hugo Pfoertner_, Mar 16 2021
%K A341257 nonn
%O A341257 1,2
%A A341257 _Clark Kimberling_, Mar 16 2021