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Search: id:A080858
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| A080858 |
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Triangle read by rows: T(n,k), n >=1, 0 <= k <= C(n,k), = number of n X n symmetric positive definite matrices with 2's on the main diagonal and 1's and 0's elsewhere and with w 1's above the diagonal. |
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+0
9
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| 1, 1, 1, 1, 3, 3, 1, 1, 6, 15, 20, 12, 6, 1, 1, 10, 45, 120, 190, 192, 140, 80, 30, 10, 1
(list; graph; listen)
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OFFSET
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1,5
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LINKS
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Index entries for sequences related to binary matrices
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EXAMPLE
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1; 1,1; 1,3,3,1; 1,6,15,20,12,6,1; ...
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CROSSREFS
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Rows sums give A085657. A085656(n) = Sum_{k=0..C(n, 2)} 2^k*T(n, k).
Sequence in context: A157636 A086626 A144163 this_sequence A144228 A083029 A084546
Adjacent sequences: A080855 A080856 A080857 this_sequence A080859 A080860 A080861
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KEYWORD
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nonn,tabf
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AUTHOR
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N. J. A. Sloane (njas(AT)research.att.com), Jul 13 2003
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