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A165329
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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)^9 = I.
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0
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1, 18, 306, 5202, 88434, 1503378, 25557426, 434476242, 7386096114, 125563633785, 2134581771744, 36287890075584, 616894130535840, 10487200206374784, 178282403291884896, 3030800852281773888, 51523614426225577248
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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^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)/(136*t^9 - 16*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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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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