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 A286183 #24 Feb 16 2025 08:33:44
%S A286183 3,15,60,207,663,2038,6107,17983,52272,150407,429223,1216490,3427635,
%T A286183 9609327,26821668,74576703,206650167,570877918,1572754187,4322192287,
%U A286183 11851474968,32430381815,88576465735,241511251922,657457204323,1787147867343,4851349002252
%N A286183 Number of connected induced (non-null) subgraphs of the antiprism graph with 2n nodes.
%H A286183 Andrew Howroyd, <a href="/A286183/b286183.txt">Table of n, a(n) for n = 1..200</a>
%H A286183 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/AntiprismGraph.html">Antiprism Graph</a>
%H A286183 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/Vertex-InducedSubgraph.html">Vertex-Induced Subgraph</a>
%F A286183 a(n) = 8*a(n-1) - 24*a(n-2) + 34*a(n-3) - 24*a(n-4) + 8*a(n-5) - a(n-6), for n > 6 (conjectured).
%F A286183 a(n) = A005248(n) - 2*n + 2*n*A001906(n) (conjectured). - _Eric W. Weisstein_, May 08 2017
%F A286183 G.f.: x*(3 - 9*x + 12*x^2 - 15*x^3 + 9*x^4 - 2*x^5) / ((1 - x)^2*(1 - 3*x + x^2)^2) (conjectured). - _Colin Barker_, May 30 2017
%t A286183 a[n_] := Block[{g = Graph@ Flatten@ Table[{i <-> Mod[i,n]+1, n+i <-> Mod[i,n] + n+1, i <-> n + Mod[i, n] + 1, i <-> n + Mod[i-1, n] + 1}, {i, n}]}, -1 + ParallelSum[ Boole@ ConnectedGraphQ@ Subgraph[g, s], {s, Subsets@ Range[2 n]}]]; Array[a, 8]
%Y A286183 Cf. A020873 (wheel), A059020 (ladder), A059525 (grid), A286139 (king), A286182 (prism), A286184 (helm), A286185 (Möbius ladder), A286186 (friendship), A286187 (web), A286188 (gear), A286189 (rook), A285765 (queen).
%K A286183 nonn
%O A286183 1,1
%A A286183 _Giovanni Resta_, May 04 2017
%E A286183 a(17)-a(27) from _Andrew Howroyd_, May 20 2017