A351157 - OEIS

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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.

1, 2, 4, 11, 33, 145, 839, 7449

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,2

LINKS

Table of n, a(n) for n=1..8.

CROSSREFS

Cf. A016121

Sequence in context: A123416 A123406 A123453 * A123459 A123426 A277204

Adjacent sequences: A351154 A351155 A351156 * A351158 A351159 A351160

KEYWORD

nonn,hard,more

AUTHOR

Max Alekseyev, Feb 02 2022

STATUS

approved