login
A164974
Number of reduced words of length n in Coxeter group on 29 generators S_i with relations (S_i)^2 = (S_i S_j)^8 = I.
0
1, 29, 812, 22736, 636608, 17825024, 499100672, 13974818816, 391294926442, 10956257929008, 306775221694326, 8589706198539984, 240511773309887520, 6734329645698353664, 188561229884155989504, 5279714431285226139648
OFFSET
0,2
COMMENTS
The initial terms coincide with those of A170748, although the two sequences are eventually different.
Computed with MAGMA using commands similar to those used to compute A154638.
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)/(378*t^8 -
27*t^7 - 27*t^6 - 27*t^5 - 27*t^4 - 27*t^3 - 27*t^2 - 27*t + 1)
MATHEMATICA
coxG[{8, 378, -27}] (* The coxG program is at A169452 *) (* Harvey P. Dale, Aug 26 2017 *)
CROSSREFS
Sequence in context: A163549 A164026 A164665 * A165512 A166004 A166423
KEYWORD
nonn
AUTHOR
John Cannon and N. J. A. Sloane, Dec 03 2009
STATUS
approved