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Search: id:A056080
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| A056080 |
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Number of 5 X 5 binary matrices with n ones, with no zero rows or columns, up to row and column permutation. |
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+0
5
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| 1, 2, 14, 49, 131, 248, 410, 531, 601, 566, 474, 336, 222, 124, 67, 32, 16, 6, 3, 1, 1
(list; graph; listen)
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OFFSET
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5,2
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COMMENT
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Sum_{k=0..25} a(n)=A054976(5).
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FORMULA
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G.f. : Z(S_5 X S_5; x_1, x_2, ...)-2*Z(S_5 X S_4; x_1, x_2, ...)+Z(S_4 X S_4; x_1, x_2, ...) if we replace x_i by 1+x^i, where Z(S_i X S_j; x_1, x_2, ...) is cycle index of Cartesian product of symmetric groups S_i and S_j of degree i and j, respectively.
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CROSSREFS
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Cf. A052371.
Sequence in context: A036659 A079937 A083102 this_sequence A163796 A153978 A143553
Adjacent sequences: A056077 A056078 A056079 this_sequence A056081 A056082 A056083
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KEYWORD
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fini,nonn
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AUTHOR
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Vladeta Jovovic (vladeta(AT)eunet.rs), Aug 04 2000
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