login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A165745 Number of reduced words of length n in Coxeter group on 3 generators S_i with relations (S_i)^2 = (S_i S_j)^10 = I. 0
1, 3, 6, 12, 24, 48, 96, 192, 384, 768, 1533, 3060, 6111, 12204, 24372, 48672, 97200, 194112, 387648, 774144, 1545990, 3087393, 6165624, 12312951, 24589362, 49105752, 98065776, 195840528, 391099872, 781039104, 1559760372, 3114891948 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

The initial terms coincide with those of A003945, 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..31.

Index entries for linear recurrences with constant coefficients, signature (1, 1, 1, 1, 1, 1, 1, 1, 1, -1).

FORMULA

G.f. (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^10 - t^9 - t^8 - t^7 - t^6 - t^5 - t^4 - t^3 - t^2 - t + 1)

CROSSREFS

Sequence in context: A164696 A165183 A046944 * A166327 A166467 A166857

Adjacent sequences:  A165742 A165743 A165744 * A165746 A165747 A165748

KEYWORD

nonn

AUTHOR

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

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified May 24 04:25 EDT 2019. Contains 323528 sequences. (Running on oeis4.)