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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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8
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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; refs; listen; history; internal format)
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OFFSET
| 1,5
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LINKS
| Index entries for sequences related to binary matrices
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EXAMPLE
| 1; 1,1; 1,3,3,1; 1,6,15,20,12,6,1; ...
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CROSSREFS
| Rows sums give A085657. A085656(n) = Sum_{k=0..C(n, 2)} 2^k*T(n, k).
Sequence in context: A157636 A086626 A144163 * A144228 A083029 A084546
Adjacent sequences: A080855 A080856 A080857 * A080859 A080860 A080861
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KEYWORD
| nonn,tabf
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AUTHOR
| N. J. A. Sloane (njas(AT)research.att.com), Jul 13 2003
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