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A165709
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.
0
1, 49, 2352, 112896, 5419008, 260112384, 12485394432, 599298932736, 28766348771328, 1380784741022568, 66277667569026816, 3181328043310578840, 152703746078777784576, 7329779811775093671936, 351829430964904976842752
OFFSET
0,2
COMMENTS
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.
FORMULA
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)
MATHEMATICA
coxG[{9, 1128, -47}] (* The coxG program is at A169452 *) (* Harvey P. Dale, Sep 01 2015 *)
CROSSREFS
Sequence in context: A164350 A164694 A165181 * A166324 A166443 A166855
KEYWORD
nonn
AUTHOR
John Cannon and N. J. A. Sloane, Dec 03 2009
STATUS
approved