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 A075464 #36 Feb 16 2025 08:32:47 %S A075464 1,4,5,4,15,28,33,40,25,44,55,72,105,56,117,104,147,188,141,224,245, %T A075464 276,231,270,353,356,405,416,345,376,553,428,469,520,563,600,761,772, %U A075464 561,696,891,940,953,772,1069,1188,971,1096,1165,1220,1317,1256,1487,1400 %N A075464 a(n) is the minimal number of nontrivial switch flippings needed to solve the all-ones lights out problem on an n X n square. %C A075464 For squares having multiple possible solutions (see A075462, A075463), there may be nontrivial solutions involving *more* than this number of flips. %D A075464 See A075462 for references. %H A075464 Zhao Hui Du, <a href="/A075464/b075464.txt">Table of n, a(n) for n = 1..78</a> (terms 1..60 from Max Alekseyev) %H A075464 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/LightsOutPuzzle.html">Lights Out Puzzle</a> %H A075464 Zhao Hui Du, <a href="/A075464/a075464.c.txt">C code for the problem</a> (please compile it using the latest gcc with option -O3 -msse4.2) %Y A075464 Cf. A075462, A075463. %K A075464 nonn,nice %O A075464 1,2 %A A075464 _Eric W. Weisstein_, Sep 17 2002 %E A075464 a(26)-a(29) from _Les Reid_, Sep 09 2007 %E A075464 a(30)-a(38) from _Max Alekseyev_, Sep 17 2009 %E A075464 Extended by _Max Alekseyev_, Sep 20 2009