%I #8 Aug 16 2017 03:57:23
%S 1,7,47,492,10030,415504,34821705,5873737591,1986293769719,
%T 1342287826603144,1808263364071413240,4847274244238104590520,
%U 25819608749278516743821755,272991106439478141199607596649,5724287949499035173796596544768241,237885203520333624684917852305536258876
%N Number of connected (non-null) inducted subgraphs in the n-triangular grid graph.
%H Andrew Howroyd, <a href="/A288722/b288722.txt">Table of n, a(n) for n = 1..20</a>
%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/TriangualrGridGraph.html">Triangular Grid Graph</a>
%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/Vertex-InducedSubgraph.html">Vertex-Induced Subgraph</a>
%Y Cf. A288721.
%K nonn
%O 1,2
%A _Eric W. Weisstein_, Jun 14 2017
%E a(8)-a(16) from _Andrew Howroyd_, Aug 15 2017