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Search: id:A162805
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| A162805 |
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Number of reduced words of length n in Coxeter group on 19 generators S_i with relations (S_i)^2 = (S_i S_j)^3 = I. |
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+0
1
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| 1, 19, 342, 5985, 104652, 1828503, 31947930, 558187605, 9752543136, 170394389307, 2977095147966, 52015183033833, 908798387526612, 15878335141888767, 277422946995884994, 4847075643050582301
(list; graph; listen)
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OFFSET
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0,2
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COMMENT
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The initial terms coincide with those of A170738, although the two sequences are eventually different.
Computed with MAGMA using commands similar to those used to compute A154638.
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FORMULA
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G.f.: (t^3 + 2*t^2 + 2*t + 1)/(153*t^3 - 17*t^2 - 17*t + 1)
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CROSSREFS
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Sequence in context: A142549 A049629 A144745 this_sequence A049664 A163110 A163453
Adjacent sequences: A162802 A162803 A162804 this_sequence A162806 A162807 A162808
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KEYWORD
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nonn
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AUTHOR
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John Cannon (john(AT)maths.usyd.edu.au) and N. J. A. Sloane (njas(AT)research.att.com), Dec 03 2009
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