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A210206
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Maximal number of 1s in a Hadamard matrix of order 4n.
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0
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12, 42, 90, 160, 240, 344, 462, 598, 756, 922, 1108, 1314, 1534, 1772
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OFFSET
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1,1
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COMMENTS
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The weight of a {-1,1} matrix is defined to be the number of elements equal to 1. The excess is defined to be the sum of the matrix elements. The weight and excess of an N x N matrix are related by (weight) = (excess + N^2) / 2. Hence a(n) = (A004118+16n^2)/2. - William P. Orrick, Jun 25 2015
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LINKS
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N. J. A. Sloane, Hadamard matrices, gives representatives of all Hadamard matrix equivalence classes for sizes up to 28, and a representative of at least one equivalence class for sizes up to 256. Most are not of maximal weight, however.
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CROSSREFS
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KEYWORD
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nonn,more
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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