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Search: id:A083029
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| A083029 |
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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 semi-definite matrices with 2's on the main diagonal and 1's and 0's elsewhere and with k 1's above the diagonal. |
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+0
10
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| 1, 1, 1, 1, 3, 3, 1, 1, 6, 15, 20, 15, 6, 1, 1, 10, 45, 120, 210, 192, 200, 90, 45, 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; 1,6,15,20,15,6,1; ...
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CROSSREFS
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Rows sums give A085658. A038379(n) = Sum_{k=0..C(n, 2)} 2^k*T(n, k).
A084546 is an upper bound.
Sequence in context: A144163 A080858 A144228 this_sequence A084546 A026515 A075772
Adjacent sequences: A083026 A083027 A083028 this_sequence A083030 A083031 A083032
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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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