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A164686
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Number of reduced words of length n in Coxeter group on 42 generators S_i with relations (S_i)^2 = (S_i S_j)^7 = I.
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0
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1, 42, 1722, 70602, 2894682, 118681962, 4865960442, 199504377261, 8179679432400, 335366855281920, 13750041007253040, 563751678865841760, 23113818733806664080, 947666563998666456000, 38854328956361647813980
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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 A170761, 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^7 + 2*t^6 + 2*t^5 + 2*t^4 + 2*t^3 + 2*t^2 + 2*t + 1)/(820*t^7 - 40*t^6 - 40*t^5 - 40*t^4 - 40*t^3 - 40*t^2 - 40*t + 1).
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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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