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 A287230 #19 Sep 02 2025 21:55:29 %S A287230 1,1,8,64,1331,64000,6400075,1404928000,677298787768,712186032947200, %T A287230 1635557819719974912,8209592592625295700893, %U A287230 90036881979773511965369428,2157454308508779392217680572439,112955975573487831948842897960075264,12921763288870998051759383983484279183072,3229803978189426975602886931834056243712000000 %N A287230 Number of matchings in the n-triangular honeycomb acute knight graph. %H A287230 Stan Wagon, <a href="http://www.jstor.org/stable/10.4169/college.math.j.45.4.278">Graph Theory Problems from Hexagonal and Traditional Chess</a>, The College Mathematics Journal, Vol. 45, No. 4, September 2014, pp. 278-287. %H A287230 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/IndependentEdgeSet.html">Independent Edge Set</a> %H A287230 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/Matching.html">Matching</a> %Y A287230 Cf. A289143, A287204, A289904, A287228, A269869. %K A287230 nonn,changed %O A287230 1,3 %A A287230 _Eric W. Weisstein_, May 22 2017 %E A287230 a(11) from _Eric W. Weisstein_, Jun 25 2017 %E A287230 a(12)-a(14) from _Andrew Howroyd_, Jul 17 2017 %E A287230 a(15)-a(17) from _Eric W. Weisstein_, Sep 02 2025