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Search: id:A094813
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| A094813 |
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a(n) = number of (0,1) matrices of size n X n whose determinants are k, where -L <= k <= +L and L = A003432(n). |
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+0
1
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| 1, 13, 10, 33, 84, 338, 84, 360, 1200, 10020, 42976, 10020, 12003600, 42795, 145485, 1206772, 4848581, 21059938, 4848585, 1206796, 145473, 42807, 3600
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OFFSET
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1,2
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REFERENCES
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J. Brenner, The Hadamard maximum determinant problem, Amer. Math. Monthly, 79 (1972), 626-630
J. Williamson, Determinants whose elements are 0 and 1, Amer. Math. Monthly 53 (1946), 427-434. Math. Rec. 8,128g
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EXAMPLE
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n = 2 : det([a b];[c d]) is (ad - bc) [16 possible matrices]
0 if ((a OR d) = zero) AND ((b OR c) = zero)
OR ((a AND d) = one) AND ((b AND D) = one) [10 possible matrices]
+1 if ((a AND d) = one) AND ((b OR c) = zero) [ 3 possible matrices]
-1 if ((a OR d) = zero) AND ((b AND c) = one) [ 3 possible matrices]
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CROSSREFS
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Cf. A003432, A003433.
Sequence in context: A166522 A066552 A072270 this_sequence A152298 A158956 A160130
Adjacent sequences: A094810 A094811 A094812 this_sequence A094814 A094815 A094816
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KEYWORD
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hard,nonn
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AUTHOR
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Patricia J. Egan (capdevcom(AT)lycos.com), Jun 11 2004
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