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 A333825 #15 Apr 12 2020 13:57:57 %S A333825 1,2,3,4,17,20,22,27,45,48,67,79,80,131,135,174,180,194,201,209,236, %T A333825 254,312,319,394,523,644,656,706,711,733,765,766,845,848,921,922,935, %U A333825 1034,1051,1219,1292,1310,1330,1399,1410,1546,1589,1674,1792,1816,1863 %N A333825 Lexicographically earliest sequence of distinct positive integers, which when mapped onto a square spiral, gives a set without three distinct aligned points. %C A333825 This sequence has similarities with A236266. %H A333825 Rémy Sigrist, <a href="/A333825/b333825.txt">Table of n, a(n) for n = 1..10000</a> %H A333825 Rémy Sigrist, <a href="/A333825/a333825.png">Scatterplot of (A174344(a(n)), A274923(a(n))) in the region -20000 <= x, y <= 20000</a> %H A333825 Rémy Sigrist, <a href="/A333825/a333825.txt">C# program for A333825</a> %e A333825 The first terms, mapped onto a square spiral, are: %e A333825 *---*---*---*---*---*---*---*---* %e A333825 | | %e A333825 * *---*---*---*---*---*---* * %e A333825 | | | | %e A333825 67 * 17---*---*---*---* * * %e A333825 | | | | | | %e A333825 * * * *---4---3 * * * %e A333825 | | | | | | | | %e A333825 * * * * 1---2 * * * %e A333825 | | | | | | | %e A333825 * * 20 *---*---*---* 27 * %e A333825 | | | | | %e A333825 * * *--22---*---*---*---* * %e A333825 | | | %e A333825 * *---*--45---*---*--48---*---* %e A333825 | %e A333825 *---*---*---*---*---*--79--80---* %o A333825 (C#) See Links section. %Y A333825 See A333835 and A333866 for a similar sequences. %Y A333825 Cf. A174344, A236266, A274923. %K A333825 nonn %O A333825 1,2 %A A333825 _Rémy Sigrist_, Apr 07 2020