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A306837
Number of unimodular n X n matrices with elements {0, 1}.
2
1, 6, 168, 20040, 9702720, 18480102480, 135491563468800, 3766962568171582080
OFFSET
1,2
COMMENTS
An integer matrix is unimodular if its determinant is -1 or +1.
LINKS
Steven Finch, Small Matrices with Large Inverses: Unimodular 4 X 4 Cases, arXiv:2607.07688 [math.CO], 2026. See p. 17.
Steven E. Thornton, Properties of the Bohemian family of n x n matrices with population {0, 1}, Characteristic Polynomial Database.
CROSSREFS
Number of different values taken by the determinant is in A089472.
Maximum determinant is in A003432.
A363862 gives equivalence classes up to row and column permutation.
Sequence in context: A322708 A181013 A003720 * A002884 A198176 A264358
KEYWORD
nonn,more,hard
AUTHOR
Steven E. Thornton, Mar 12 2019
EXTENSIONS
a(7) and a(8) from Brendan McKay, Jun 25 2023
STATUS
approved