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Search: id:A163020
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| A163020 |
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Number of nX3 binary arrays with all 1s connected and a path of 1s from left column to lower right corner |
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+0
1
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| 1, 12, 82, 469, 2502, 12966, 66325, 337222, 1709652, 8655795, 43794966, 221516992, 1120277983, 5665183308, 28647552996, 144861882889, 732516467528, 3704069018506, 18730095418683, 94711027286382, 478917748054834
(list; graph; listen)
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OFFSET
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1,2
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LINKS
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R. H. Hardin, Table of n, a(n) for n=1..100
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FORMULA
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Empirical: a(n)= 10*a(n-1) -33*a(n-2) +45*a(n-3) -21*a(n-4) -15*a(n-5) +29*a(n-6) -9*a(n-7) -6*a(n-8) +a(n-9). G.f.: x*(-1-2*x+5*x^2+x^4+x^6)/((x-1) *(x^2+2*x-1) *(x^6-7*x^5+x^4+6*x^3-11*x^2+7* x-1) [From R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Aug 11 2009]
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CROSSREFS
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Sequence in context: A147650 A007010 A069996 this_sequence A164300 A175037 A102105
Adjacent sequences: A163017 A163018 A163019 this_sequence A163021 A163022 A163023
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KEYWORD
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nonn
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AUTHOR
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Ron Hardin (rhhardin(AT)att.net) Jul 20 2009
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