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A164049 Number of reduced words of length n in Coxeter group on 33 generators S_i with relations (S_i)^2 = (S_i S_j)^6 = I. 1
1, 33, 1056, 33792, 1081344, 34603008, 1107295728, 35433446400, 1133869744656, 36283814544384, 1161081512312832, 37154590694572032, 1188946335844548336, 38046264622817975040, 1217479887955809181968, 38959337855415022281984 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

The initial terms coincide with those of A170752, although the two sequences are eventually different.

Computed with MAGMA using commands similar to those used to compute A154638.

LINKS

G. C. Greubel, Table of n, a(n) for n = 0..660

Index entries for linear recurrences with constant coefficients, signature (31, 31, 31, 31, 31, -496).

FORMULA

G.f.: (t^6 + 2*t^5 + 2*t^4 + 2*t^3 + 2*t^2 + 2*t + 1)/(496*t^6 - 31*t^5 - 31*t^4 - 31*t^3 - 31*t^2 - 31*t + 1).

MATHEMATICA

CoefficientList[Series[(t^6 + 2*t^5 + 2*t^4 + 2*t^3 + 2*t^2 + 2*t + 1)/(496*t^6 - 31*t^5 - 31*t^4 - 31*t^3 - 31*t^2 - 31*t + 1), {t, 0, 50}], t] (* G. C. Greubel, Sep 08 2017 *)

PROG

(PARI) t='t+O('t^50); Vec((t^6 + 2*t^5 + 2*t^4 + 2*t^3 + 2*t^2 + 2*t + 1)/(496*t^6 - 31*t^5 - 31*t^4 - 31*t^3 - 31*t^2 - 31*t + 1)) \\ G. C. Greubel, Sep 08 2017

CROSSREFS

Sequence in context: A162837 A163216 A163567 * A164669 A165140 A165645

Adjacent sequences:  A164046 A164047 A164048 * A164050 A164051 A164052

KEYWORD

nonn

AUTHOR

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

STATUS

approved

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Last modified September 25 21:33 EDT 2017. Contains 292500 sequences.