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A191874
Number of n X n (0,1) matrices that achieve the record mentioned in A191873.
4
1, 1, 1, 8, 405, 2520, 4320, 32781000, 256556160, 10590199200, 2225341641600, 28746722188800
OFFSET
1,4
COMMENTS
Also, number of directed graphs on n labeled nodes that do not contain a subgraph isomorphic to the complete directed bipartite graph K_{2,2} and have largest number of edges (=A191873(n)). - Max Alekseyev, Feb 07 2022
CROSSREFS
Cf. A191873.
Sequence in context: A221224 A281439 A220550 * A323575 A183579 A015091
KEYWORD
nonn,more
AUTHOR
R. H. Hardin and N. J. A. Sloane, Jun 18 2011
EXTENSIONS
a(8)-a(12) from Max Alekseyev, Feb 07 2022
STATUS
approved