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A352801
Number of symmetric n X n 01-matrices with maximum number of 1s and no 2 X 2 all-1 submatrix.
1
1, 1, 2, 4, 16, 170, 360, 840, 82320, 181440, 1512000, 19958400, 79833600, 259459200, 14529715200
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OFFSET
0,3
LINKS
Table of n, a(n) for n=0..14.
FORMULA
a(n) is the last element in the n-th row of triangle A350189.
Conjecture: the maximum number of 1s equals A072567(n), and so a(n) = A350189(n, A072567(n)).
CROSSREFS
Cf. A072567, A191874, A191966, A335820, A350189, A351335, A352258.
Sequence in context: A050472 A005741 A109457 * A105788 A217727 A071008
Adjacent sequences: A352798 A352799 A352800 * A352802 A352803 A352804
KEYWORD
nonn,more
AUTHOR
Max Alekseyev, Apr 03 2022
STATUS
approved

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Last modified September 4 18:23 EDT 2026. Contains 398986 sequences.
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