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 A261680 #16 Jul 27 2017 15:28:44
%S A261680 1,4,6,8,13,16,22,28,34,44,50,60,59,72,70,80,92,88,114,96,125,104,152,
%T A261680 120,172,144,188,152,215,144,242,160,272,172,302,180,329,216,352,240,
%U A261680 388,228,430,228,442,212,476,192,506,228,496,248,540,252,582,276,592
%N A261680 Number of ordered quadruples (u,v,w,x) of binary palindromes (see A006995) with u+v+w+x=n.
%C A261680 Conjecture: a(n)>0: every number is the sum of four binary palindromes. (Compare A261422, A261675.)
%H A261680 N. J. A. Sloane, <a href="/A261680/b261680.txt">Table of n, a(n) for n = 0..9999</a>
%H A261680 Aayush Rajasekaran, Jeffrey Shallit, and Tim Smith, <a href="https://arxiv.org/abs/1706.10206">Sums of Palindromes: an Approach via Nested-Word Automata</a>, preprint arXiv:1706.10206 [cs.FL], June 30 2017.
%F A261680 G.f. = (Sum_{p in A006995} x^p)^4.
%Y A261680 Cf. A006995, A261422, A261675, A261679.
%K A261680 nonn,base
%O A261680 0,2
%A A261680 _N. J. A. Sloane_, Sep 04 2015