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A164860 Number of reduced words of length n in Coxeter group on 15 generators S_i with relations (S_i)^2 = (S_i S_j)^8 = I. 0
1, 15, 210, 2940, 41160, 576240, 8067360, 112943040, 1581202455, 22136832900, 309915640125, 4338818675100, 60743457438300, 850408347952800, 11905716084771600, 166680014174856000, 2333520044280745320 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,2
COMMENTS
The initial terms coincide with those of A170734, although the two sequences are eventually different.
Computed with MAGMA using commands similar to those used to compute A154638.
LINKS
Index entries for linear recurrences with constant coefficients, signature (13, 13, 13, 13, 13, 13, 13, -91).
FORMULA
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)/(91*t^8 -
13*t^7 - 13*t^6 - 13*t^5 - 13*t^4 - 13*t^3 - 13*t^2 - 13*t + 1)
MATHEMATICA
coxG[{8, 91, -13}] (* The coxG program is at A169452 *) (* Harvey P. Dale, Apr 05 2022 *)
CROSSREFS
Sequence in context: A163440 A163962 A164626 * A165282 A165875 A166382
KEYWORD
nonn
AUTHOR
John Cannon and N. J. A. Sloane, Dec 03 2009
STATUS
approved

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Last modified July 19 22:34 EDT 2024. Contains 374441 sequences. (Running on oeis4.)