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A164892
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Number of reduced words of length n in Coxeter group on 18 generators S_i with relations (S_i)^2 = (S_i S_j)^8 = I.
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0
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1, 18, 306, 5202, 88434, 1503378, 25557426, 434476242, 7386095961, 125563628736, 2134581644448, 36287887206528, 616894069776480, 10487198969713728, 178282378804864032, 3030800377118109696, 51523605347410047672
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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 A170737, 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^8 + 2*t^7 + 2*t^6 + 2*t^5 + 2*t^4 + 2*t^3 + 2*t^2 + 2*t + 1)/(136*t^8 -
16*t^7 - 16*t^6 - 16*t^5 - 16*t^4 - 16*t^3 - 16*t^2 - 16*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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