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 A266529 #20 Feb 12 2017 07:02:38
%S A266529 0,0,1,1,1,1,3,3,1,1,3,3,5,5,7,7,1,1,3,3,5,5,7,7,5,5,11,11,17,17,15,
%T A266529 15,1,1,3,3,5,5,7,7,5,5,11,11,17,17,15,15,5,5,11,11,17,17,19,19,21,21,
%U A266529 39,39,49,49,31,31,1,1,3,3,5,5,7,7,5,5,11,11,17,17,15,15,5,5,11,11,17,17,19,19,21,21
%N A266529 Terms of A160552 repeated.
%C A266529 First differs from A266509 at a(55), with which it shares infinitely many terms.
%C A266529 First differs from A266539 at a(25), with which it shares infinitely many terms.
%H A266529 Ivan Neretin, <a href="/A266529/b266529.txt">Table of n, a(n) for n = 1..8192</a>
%e A266529 Written as an irregular triangle in which the row lengths are twice the terms of A011782 the sequence begins:
%e A266529 0,0;
%e A266529 1,1;
%e A266529 1,1,3,3;
%e A266529 1,1,3,3,5,5,7,7;
%e A266529 1,1,3,3,5,5,7,7,5,5,11,11,17,17,15,15;
%e A266529 1,1,3,3,5,5,7,7,5,5,11,11,17,17,15,15,5,5,11,11,17,17,19,19,21,21,39,39,49,49,31,31;
%e A266529 ...
%e A266529 Row sums give 0 together with A004171.
%t A266529 Riffle[#, #] &@ Table[SeriesCoefficient[x (1 + 2 x)/(1 + x) + (4 x^2/(1 + 2 x)) (Product[1 + x^(2^k - 1) + 2 x^(2^k), {k, 20}] - 1), {x, 0, n}], {n, 0, 44}] (* _Michael De Vlieger_, Jan 05 2016, based on Maple by _N. J. A. Sloane_ at A160552 *)
%Y A266529 Partial sums give A266530.
%Y A266529 Cf. A004171, A011782, A139250, A160552, A255747, A266509, A266539.
%K A266529 nonn,tabf
%O A266529 1,7
%A A266529 _Omar E. Pol_, Jan 02 2016