A367457 Number of maximal independent vertex sets in the n X n camel graph.

1, 1, 1, 25, 300, 4761, 37908, 1408969, 42742245, 1650878161, 240427884762, 14943334966921, 4986511832627632, 793446864376246336, 451148370226544277049

Offset

1,4

Links

Table of n, a(n) for n=1..15.

Eric Weisstein's World of Mathematics, Camel Graph.

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

Mathematica

Table[Length@FindIndependentVertexSet[RelationGraph[Sort[Abs[Subtract[##]]] == {1, 3} &, Tuples[Range[n], 2]], Infinity, All], {n, 8}]

Prog

(Python)
from networkx import empty_graph, complement, find_cliques
def A367457(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 ((1, 3), (1, -3), (-1, 3), (-1, -3), (3, 1), (3, -1), (-3, 1), (-3, -1)) 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: A078488 A010941 A022620 * A042206 A269448 A128377

Adjacent sequences: A367454 A367455 A367456 * A367458 A367459 A367460

Keyword

nonn,more

Author

Eric W. Weisstein, Jan 26 2024

Status

approved