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 A288722 #14 Aug 28 2025 10:19:42 %S A288722 1,7,47,492,10030,415504,34821705,5873737591,1986293769719, %T A288722 1342287826603144,1808263364071413240,4847274244238104590520, %U A288722 25819608749278516743821755,272991106439478141199607596649,5724287949499035173796596544768241,237885203520333624684917852305536258876 %N A288722 Number of connected (non-null) inducted subgraphs in the n-triangular grid graph. %H A288722 Andrew Howroyd, <a href="/A288722/b288722.txt">Table of n, a(n) for n = 1..20</a> %H A288722 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/TriangualrGridGraph.html">Triangular Grid Graph</a> %H A288722 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/Vertex-InducedSubgraph.html">Vertex-Induced Subgraph</a> %Y A288722 Cf. A288721. %K A288722 nonn,changed %O A288722 1,2 %A A288722 _Eric W. Weisstein_, Jun 14 2017 %E A288722 a(8) onwards from _Andrew Howroyd_, Aug 15 2017