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 A370228 #9 May 27 2025 14:59:32 %S A370228 0,0,1,7,39,237,1734,15450,165682,2102614,31015311,524013081, %T A370228 10030700577,215582832795,5159960081308,136564828657252, %U A370228 3972563571866868,126343835507748636,4372455341681750061,163953900979575446619,6635493391775352850603,288852182590324903158841 %N A370228 Number of chordless cycles in the n-triangular honeycomb bishop graph. %H A370228 Andrew Howroyd, <a href="/A370228/b370228.txt">Table of n, a(n) for n = 1..200</a> %H A370228 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 A370228 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/ChordlessCycle.html">Chordless Cycle</a>. %H A370228 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/TriangularHoneycombBishopGraph.html">Triangular Honeycomb Bishop Graph</a>. %o A370228 (PARI) \\ CCGenRook defined in A370224. %o A370228 a(n) = subst(CCGenRook(vector(n,i,n+1-i)), y, 1) \\ _Andrew Howroyd_, May 27 2025 %Y A370228 Cf. A370224. %K A370228 nonn %O A370228 1,4 %A A370228 _Eric W. Weisstein_, Feb 12 2024 %E A370228 a(12) onwards from _Andrew Howroyd_, May 27 2025