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A358159
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a(n) is the permanent of the n X n matrix M(n) that is defined by M[i,j] = i*j - floor(i*j/3).
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2
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1, 1, 7, 102, 4396, 374216, 49857920, 11344877568, 3879729283968, 1804571320405248, 1195546731955854336, 1058730877124859138048, 1184751018265831288602624, 1725335046543668616765112320, 3147123030650561978295975936000, 6934187745940804400441946931200000, 18840570649600136750602236509552640000
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OFFSET
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0,3
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COMMENTS
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The matrix M(n) is the n-th principal submatrix of the rectangular array A143976 and it is singular for n > 3.
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LINKS
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EXAMPLE
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a(5) = 374216:
1 2 2 3 4
2 3 4 6 7
2 4 6 8 10
3 6 8 11 14
4 7 10 14 17
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MATHEMATICA
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Join[{1}, Table[Permanent[Table[i*j-Floor[i*j/3], {i, n}, {j, n}]], {n, 17}]]
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PROG
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(Python)
from sympy import Matrix
def A358159(n): return Matrix(n, n, [i*j-i*j//3 for i in range(1, n+1) for j in range(1, n+1)]).per() if n else 1 # Chai Wah Wu, Nov 02 2022
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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