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A351157
Number of symmetric 0-1 matrices with zero main diagonal where rows are sorted lexicographically and row sums are nondecreasing.
2
1, 2, 4, 11, 33, 145, 839, 7449
OFFSET
1,2
CROSSREFS
Sequence in context: A123416 A123406 A123453 * A123459 A123426 A277204
KEYWORD
nonn,hard,more
AUTHOR
Max Alekseyev, Feb 02 2022
STATUS
approved