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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
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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
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Last modified April 19 05:19 EDT 2024. Contains 371782 sequences. (Running on oeis4.)