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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 (list; graph; refs; listen; history; text; internal format)
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.

LINKS

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).

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

Adjacent sequences:  A165706 A165707 A165708 * A165710 A165711 A165712

KEYWORD

nonn

AUTHOR

John Cannon and N. J. A. Sloane, Dec 03 2009

STATUS

approved

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Last modified September 25 12:25 EDT 2021. Contains 347654 sequences. (Running on oeis4.)