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A165214
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Number of reduced words of length n in Coxeter group on 7 generators S_i with relations (S_i)^2 = (S_i S_j)^9 = I.
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0
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1, 7, 42, 252, 1512, 9072, 54432, 326592, 1959552, 11757291, 70543620, 423260985, 2539561500, 15237342540, 91423896480, 548542426320, 3291248842560, 19747458763200, 118484546826660, 710906046446925, 4265428871616150
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OFFSET
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0,2
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COMMENTS
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The initial terms coincide with those of A003949, although the two sequences are eventually different.
Computed with MAGMA using commands similar to those used to compute A154638.
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LINKS
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FORMULA
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G.f. (t^9 + 2*t^8 + 2*t^7 + 2*t^6 + 2*t^5 + 2*t^4 + 2*t^3 + 2*t^2 + 2*t +
1)/(15*t^9 - 5*t^8 - 5*t^7 - 5*t^6 - 5*t^5 - 5*t^4 - 5*t^3 - 5*t^2 - 5*t
+ 1)
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MATHEMATICA
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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