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Search: id:A005321
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| A005321 |
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Upper triangular n X n (0,1)-matrices with no empty rows or columns.
(Formerly M1986)
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+0
8
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| 1, 1, 2, 10, 122, 3346, 196082, 23869210, 5939193962, 2992674197026, 3037348468846562, 6189980791404487210, 25285903982959247885402
(list; graph; listen)
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OFFSET
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0,3
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REFERENCES
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T. L. Greenough, Ph.D. Thesis, Dartmouth, circa 1975 [ from Tom Trotter ].
Andresen, E.; Kjeldsen, K.; On certain subgraphs of a complete transitively directed graph. Discrete Math. 14 (1976), no. 2, 103-119.
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LINKS
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Index entries for sequences related to binary matrices
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FORMULA
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Sum_{k=0..n} C(n, k)b(k), where b(0)=1, b(k+1) = (2^(k+1)-1)*b(k)+(-1)^(k+1) [ A005327 ].
G.f.: Sum(x^n*Product((2^i-1)/(1+(2^i-1)*x),i = 1 .. n),n = 0 .. infinity). - Vladeta Jovovic (vladeta(AT)Eunet.yu), Mar 10 2008
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CROSSREFS
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Adjacent sequences: A005318 A005319 A005320 this_sequence A005322 A005323 A005324
Sequence in context: A060690 A005617 A013038 this_sequence A092645 A119191 A125993
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KEYWORD
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nonn,easy,nice,more
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AUTHOR
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njas
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