login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A163093 Number of reduced words of length n in Coxeter group on 17 generators S_i with relations (S_i)^2 = (S_i S_j)^4 = I. 0
1, 17, 272, 4352, 69496, 1109760, 17721480, 282988800, 4518961080, 72161899200, 1152331158600, 18401221627200, 293843444945400, 4692295538064000, 74929823330517000, 1196531288107632000, 19107039891249747000, 305114439575750760000, 4872278582526960045000 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,2
COMMENTS
The initial terms coincide with those of A170736, although the two sequences are eventually different.
Computed with MAGMA using commands similar to those used to compute A154638.
LINKS
FORMULA
G.f.: (t^4 + 2*t^3 + 2*t^2 + 2*t + 1)/(120*t^4 - 15*t^3 - 15*t^2 - 15*t + 1).
MATHEMATICA
CoefficientList[Series[(t^4 + 2 t^3 + 2 t^2 + 2 t + 1)/(120 t^4 - 15 t^3 - 15 t^2 - 15 t + 1), {t, 0, 20}], t] (* Jinyuan Wang, Mar 23 2020 *)
CROSSREFS
Sequence in context: A159678 A162803 A097830 * A163451 A163965 A164628
KEYWORD
nonn
AUTHOR
John Cannon and N. J. A. Sloane, Dec 03 2009
EXTENSIONS
More terms from Jinyuan Wang, Mar 23 2020
STATUS
approved

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

License Agreements, Terms of Use, Privacy Policy. .

Last modified March 18 22:56 EDT 2024. Contains 370952 sequences. (Running on oeis4.)