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A165131 Number of reduced words of length n in Coxeter group on 32 generators S_i with relations (S_i)^2 = (S_i S_j)^8 = I. 0
1, 32, 992, 30752, 953312, 29552672, 916132832, 28400117792, 880403651056, 27292513167360, 846067907712000, 26228105124311040, 813071258396052480, 25205208996092344320, 781361478439118914560, 24222205817980629811200 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

The initial terms coincide with those of A170751, 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..15.

Index entries for linear recurrences with constant coefficients, signature (30, 30, 30, 30, 30, 30, 30, -465).

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)/(465*t^8 -

30*t^7 - 30*t^6 - 30*t^5 - 30*t^4 - 30*t^3 - 30*t^2 - 30*t + 1)

CROSSREFS

Sequence in context: A163565 A164036 A164668 * A165548 A166128 A166426

Adjacent sequences:  A165128 A165129 A165130 * A165132 A165133 A165134

KEYWORD

nonn

AUTHOR

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

STATUS

approved

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Last modified December 14 21:33 EST 2017. Contains 296020 sequences.