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A112459
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Absolute value of coefficient of term [x^(n-3)] in characteristic polynomial of maximum matrix A of size n X n, where n >= 3. Maximum matrix A(i,j) is MAX(i,j), where indices i and j run from 1 to n.
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5
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3, 23, 98, 308, 798, 1806, 3696, 6996, 12441, 21021, 34034, 53144, 80444, 118524, 170544, 240312, 332367, 452067
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OFFSET
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3,1
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LINKS
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FORMULA
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a(n) = n*(n^2-4)*(n^2-1)*(5*n+3)/6!.
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PROG
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(Octave, MATLAB) for n=3:20 a = zeros(n); for i=1:n for j=1:n a(i, j) = max(i, j); end end b = poly(a); b(4) end
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CROSSREFS
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KEYWORD
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easy,nonn
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AUTHOR
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EXTENSIONS
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Offset changed from 1 to 3 and formulas adapted by Bruno Berselli, Mar 29 2012
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STATUS
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approved
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