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 A306189 #21 Jun 15 2025 17:44:57
%S A306189 3,6,2,392,1656976026,122836566640423857273582993856,
%T A306189 50043395758253154294953783566500246788902420299683914045600060272160541415159062540151890
%N A306189 Number of minimum dominating sets in the n-Sierpinski gasket graph.
%H A306189 Christian Sievers, <a href="/A306189/b306189.txt">Table of n, a(n) for n = 1..9</a>
%H A306189 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/MinimumDominatingSet.html">Minimum Dominating Set</a>.
%H A306189 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/SierpinskiGasketGraph.html">Sierpinski Gasket Graph</a>.
%o A306189 (PARI) a(n)={my(s=[[1+O(x),0,0,0],[0,0,x+O(x^2)],[0,x^2+O(x^3)],[x^3+O(x^4)]]);for(k=2,n,s=vector(4,i,vector(5-i,j,sum(xy=0,3,sum(xz=0,3,sum(yz=0,3,s[1+(i>1)+!xy+!xz][1+(j>3)+(xy%2)+(xz%2)]*s[1+(i>2)+!xy+!yz][1+(j>2)+(xy\2)+(yz%2)]*s[1+(i>3)+!xz+!yz][1+(j>1)+(xz\2)+(yz\2)]/x^(!xy+!xz+!yz)))))));pollead([1,3,3,1]*vectorv(4,i,s[i][5-i]))} \\ _Christian Sievers_, Jul 21 2024, improved Jul 25 2024
%Y A306189 Cf. A347508, A347515, A376478 (domination number).
%K A306189 nonn
%O A306189 1,1
%A A306189 _Eric W. Weisstein_, Jan 28 2019
%E A306189 a(5) and beyond from _Christian Sievers_, Jul 21 2024