

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
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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



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



CROSSREFS



KEYWORD

nonn


AUTHOR



STATUS

approved



