OFFSET
1,5
LINKS
Eric Weisstein's World of Mathematics, Antelope Graph.
Eric Weisstein's World of Mathematics, Maximal Independent Vertex Set.
MATHEMATICA
Table[Length@FindIndependentVertexSet[RelationGraph[Sort[Abs[Subtract[##]]] == {3, 4} &, Tuples[Range[n], 2]], Infinity, All], {n, 7}]
PROG
(Python)
from networkx import empty_graph, find_cliques, complement
def A321242(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 ((3, 4), (3, -4), (-3, 4), (-3, -4), (4, 3), (4, -3), (-4, 3), (-4, -3)) if 0<=i+k<n and 0<=j+l<n)
return sum(1 for c in find_cliques(complement(G))) # Chai Wah Wu, Jan 11 2024
CROSSREFS
KEYWORD
nonn,more
AUTHOR
Eric W. Weisstein, Nov 01 2018
EXTENSIONS
a(10) from Chai Wah Wu, Jan 11 2024
a(11) from Eric W. Weisstein, Jan 26 2024
STATUS
approved