A290784 Number of (non-null) connected induced subgraphs in the n-triangular honeycomb obtuse knight graph.

1, 3, 6, 19, 213, 379687, 80990506, 22635546606

Offset

1,2

Links

Table of n, a(n) for n=1..8.

Eric Weisstein's World of Mathematics, Connected Graph

Eric Weisstein's World of Mathematics, Vertex-Induced Subgraph

Mathematica

Table[With[{g = GraphData[{"TriangularHoneycombObtuseKnight", n}]}, Count[Subgraph[g, #] & /@ Rest[Subsets[VertexList[g]]], _?ConnectedGraphQ]], {n, 5}]
Table[With[{g = GraphData[{"TriangularHoneycombObtuseKnight", n}]}, Total[Boole[ConnectedGraphQ[Subgraph[g, #]]] & /@ Rest[Subsets[VertexList[g]]]]], {n, 5}]

Crossrefs

Sequence in context: A269306 A326317 A306522 * A355605 A356912 A176993

Adjacent sequences: A290781 A290782 A290783 * A290785 A290786 A290787

Keyword

nonn,more

Author

Eric W. Weisstein, Aug 10 2017

Extensions

a(8) from Andrew Howroyd, Aug 15 2017

a(2)-a(5) corrected by Eric W. Weisstein, Aug 27 2017

Status

approved