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 A297564 #17 May 13 2025 14:50:06 %S A297564 3,12,240,344064,135239930216448, %T A297564 972994892914558418965586768125212229632, %U A297564 41146466050197558152623700055749184719621958256873764134791737821244302120007939929484006451701147677119500779520 %N A297564 Number of maximum matchings in the n-Hanoi graph. %H A297564 Christian Sievers, <a href="/A297564/b297564.txt">Table of n, a(n) for n = 1..9</a> %H A297564 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/HanoiGraph.html">Hanoi Graph</a>. %H A297564 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/Matching.html">Matching</a>. %H A297564 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/MaximumIndependentEdgeSet.html">Maximum Independent Edge Set</a>. %o A297564 (PARI) rd(p)=if(p,pollead(p)*x^poldegree(p),0); %o A297564 a(n)=my(s=[1,0,x,0]);for(k=2,n,s=vector(4,i,rd(sum(xy=0,3,sum(xz=0,3,sum(yz=0,3,s[1+(i>1)+(xy%2)+(xz%2)]*s[1+(i>2)+(xy\2)+(yz%2)]*s[1+(i>3)+(xz\2)+(yz\2)]*x^(!xy+!xz+!yz)))))));pollead([1,3,3,1]*s~) \\ _Christian Sievers_, May 13 2025 %Y A297564 Cf. A286017, A297480. %K A297564 nonn %O A297564 1,1 %A A297564 _Eric W. Weisstein_, Dec 31 2017 %E A297564 a(5) and beyond from _Christian Sievers_, May 13 2025