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 A295266 #4 Nov 21 2017 20:03:08 %S A295266 1,2,3,5,7,17 %N A295266 Positive integers whose squares can be represented as the sum or difference of 3-smooth numbers. %C A295266 In Chapter 7 of de Weger's tract, it is shown that there are no other terms. %C A295266 More generally, de Weger exposited how one can determine all squares which can be represented as the sum or difference of k-smooth numbers for any given k and determined all integers whose squares can be represented as the sum or difference of 7-smooth numbers, among which the largest one is 14117^2 = 199289869 = 3^13 * 5^3 - 2 * 7^3. %H A295266 B. M. M. de Weger, <a href="https://www.win.tue.nl/~bdeweger/proefschrift.html">Algorithms for Diophantine Equations</a>, Centrum voor Wiskunde en Informatica, Amsterdam, 1989. %e A295266 a(6) = 17 ; 17^2 = 288 + 1 = 2^5 * 3^2 + 1. %Y A295266 Cf. A003586 (3-smooth numbers). %Y A295266 Coincides with A192579 and A215658 except the term 1. %K A295266 nonn,fini,full %O A295266 1,2 %A A295266 _Tomohiro Yamada_, Nov 19 2017