The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A168729

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A168729

Number of reduced words of length n in Coxeter group on 4 generators S_i with relations (S_i)^2 = (S_i S_j)^18 = I.
(history; published version)

#14 by Ray Chandler at Thu Nov 24 13:23:50 EST 2016

STATUS

editing

approved

#13 by Ray Chandler at Thu Nov 24 13:23:47 EST 2016

LINKS

<a href="/index/Rec#order_18">Index entries for linear recurrences with constant coefficients</a>, signature (2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, -3).

STATUS

approved

editing

#12 by Harvey P. Dale at Wed Sep 07 17:56:57 EDT 2016

STATUS

editing

approved

#11 by Harvey P. Dale at Wed Sep 07 17:56:46 EDT 2016

MATHEMATICA

coxG[{18, 3, -2, 30}] (* The coxG program is at A169452 *) (* Harvey P. Dale, Sep 07 2016 *)

STATUS

approved

editing

#10 by Bruno Berselli at Tue Aug 09 02:59:12 EDT 2016

STATUS

editing

approved

#9 by Bruno Berselli at Tue Aug 09 02:59:03 EDT 2016

KEYWORD

nonn,easy,changed

STATUS

proposed

editing

#8 by G. C. Greubel at Sat Aug 06 23:17:01 EDT 2016

STATUS

editing

proposed

#7 by G. C. Greubel at Sat Aug 06 23:16:57 EDT 2016

COMMENTS

First disagreement at index 18: a(18) = 516560646, A003946(18) = 516560652. - _Klaus Brockhaus, _, Mar 27 2011

LINKS

G. C. Greubel, <a href="/A168729/b168729.txt">Table of n, a(n) for n = 0..500</a>

MATHEMATICA

CoefficientList[Series[(t^18 + 2*t^17 + 2*t^16 + 2*t^15 + 2*t^14 + 2*t^13 + 2*t^12 + 2*t^11 + 2*t^10 + 2*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)/(3*t^18 - 2*t^17 - 2*t^16 - 2*t^15 - 2*t^14 - 2*t^13 - 2*t^12 - 2*t^11 - 2*t^10 - 2*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), {t, 0, 50}], t] (* G. C. Greubel, Aug 06 2016 *)

STATUS

approved

editing

#6 by N. J. A. Sloane at Sun Jul 13 09:05:43 EDT 2014

AUTHOR

_John Cannon (john(AT)maths.usyd.edu.au) _ and N. J. A. Sloane, Dec 03 2009

Discussion

Sun Jul 13

09:05

OEIS Server: https://oeis.org/edit/global/2246

#5 by Russ Cox at Fri Mar 30 16:51:35 EDT 2012

AUTHOR

John Cannon (john(AT)maths.usyd.edu.au) and _N. J. A. Sloane (njas(AT)research.att.com), _, Dec 03 2009

Discussion

Fri Mar 30

16:51

OEIS Server: https://oeis.org/edit/global/110