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 A076280 #19 Feb 16 2025 08:32:47 %S A076280 0,0,0,1,4,31,318,5366,155291,7855628,675054876 %N A076280 Number of 4-chromatic (i.e., chromatic number equals 4) simple graphs on n nodes. %H A076280 Keith M. Briggs, <a href="http://keithbriggs.info/cgt.html">Combinatorial Graph Theory</a> %H A076280 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/n-ChromaticGraph.html">n-Chromatic Graph</a> %Y A076280 Column k=4 of A084268. %Y A076280 Cf. A076278, A076279, A076281, A076282. %K A076280 nonn,more %O A076280 1,5 %A A076280 _Eric W. Weisstein_, Oct 06 2002 %E A076280 a(10) from _Keith Briggs_, Feb 24 2006 %E A076280 a(11) from _Michael Sollami_, Jan 28 2012