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A165709
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Number of reduced words of length n in Coxeter group on 49 generators S_i with relations (S_i)^2 = (S_i S_j)^9 = I.
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0
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1, 49, 2352, 112896, 5419008, 260112384, 12485394432, 599298932736, 28766348771328, 1380784741022568, 66277667569026816, 3181328043310578840, 152703746078777784576, 7329779811775093671936, 351829430964904976842752
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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 A170768, 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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Table of n, a(n) for n=0..14.
Index entries for linear recurrences with constant coefficients, signature (47, 47, 47, 47, 47, 47, 47, 47, -1128).
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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)/(1128*t^9 - 47*t^8 - 47*t^7 - 47*t^6 - 47*t^5 - 47*t^4 - 47*t^3 -
47*t^2 - 47*t + 1)
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MATHEMATICA
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coxG[{9, 1128, -47}] (* The coxG program is at A169452 *) (* Harvey P. Dale, Sep 01 2015 *)
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CROSSREFS
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Sequence in context: A164350 A164694 A165181 * A166324 A166443 A166855
Adjacent sequences: A165706 A165707 A165708 * A165710 A165711 A165712
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KEYWORD
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nonn
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AUTHOR
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John Cannon and N. J. A. Sloane, Dec 03 2009
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STATUS
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approved
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