A367089 Number of maximal independent vertex sets in the n X n zebra graph.

1, 1, 1, 16, 900, 5620, 15022, 134232, 8215633, 1062549091, 129577107261

Offset

1,4

Links

Table of n, a(n) for n=1..11.

Eric Weisstein's World of Mathematics, Matching.

Eric Weisstein's World of Mathematics, Maximal Independent Vertex Set.

Eric Weisstein's World of Mathematics, Zebra Graph.

Mathematica

Table[Length@FindIndependentVertexSet[RelationGraph[Sort[Abs[Subtract[##]]] == {2, 3} &, Tuples[Range[n], 2]], Infinity, All], {n, 8}]

Prog

(Python)
from networkx import empty_graph, complement, find_cliques
def A367089(n):
    G = empty_graph((i, j) for i in range(n) for j in range(n))
    G.add_edges_from(((i, j), (i+k, j+l)) for i in range(n) for j in range(n) for (k, l) in ((2, 3), (2, -3), (-2, 3), (-2, -3), (3, 2), (3, -2), (-3, 2), (-3, -2)) if 0<=i+k<n and 0<=j+l<n)
    return sum(1 for c in find_cliques(complement(G))) # Chai Wah Wu, Jan 27 2024

Crossrefs

Sequence in context: A264125 A272468 A214386 * A185561 A369583 A283946

Adjacent sequences: A367086 A367087 A367088 * A367090 A367091 A367092

Keyword

nonn,more

Author

Eric W. Weisstein, Jan 26 2024

Status

approved