A297532 - OEIS

%I #10 Feb 16 2025 08:33:52

%S 3,2,144,8192,69269232549888,2658455991569831745807614120560689152,

%T 20629598047085351073781197562197536448467995509610681744292843893938924076606720567385132001811808287432516829184

%N Number of maximum matchings in the n-Sierpinski sieve graph.

%H Christian Sievers, <a href="/A297532/b297532.txt">Table of n, a(n) for n = 1..9</a>

%H Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/Matching.html">Matching</a>

%H Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/MaximumIndependentEdgeSet.html">Maximum Independent Edge Set</a>

%H Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/SierpinskiSieveGraph.html">Sierpinski Sieve Graph</a>

%o (PARI) rd(p)=if(p,pollead(p)*x^poldegree(p),0);

%o a(n)={my(s=[1,0,x,0]);for(k=2,n,s=vector(4,i,sum(xy=0,2,sum(xz=0,2,sum(yz=0,2,rd(s[1+(i>1)+(xy%2)+(xz%2)]*s[1+(i>2)+(xy\2)+(yz%2)]*s[1+(i>3)+(xz\2)+(yz\2)]))))));pollead([1,3,3,1]*s~)} \\ _Christian Sievers_, Jul 21 2024

%K nonn

%O 1,1

%A _Eric W. Weisstein_, Dec 31 2017

%E a(5) and beyond from _Christian Sievers_, Jul 21 2024