A164835 Number of reduced words of length n in Coxeter group on 14 generators S_i with relations (S_i)^2 = (S_i S_j)^8 = I.

1, 14, 182, 2366, 30758, 399854, 5198102, 67575326, 878479147, 11420227728, 148462945176, 1930018088544, 25090232567400, 326172989788464, 4240248430609464, 55123223921595648, 716601837188495622

Offset: 0

Author

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

Keywords

• nonn

Comments

The initial terms coincide with those of A170733, although the two sequences are eventually different.

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

Links

• Index entries for linear recurrences with constant coefficients, signature (12, 12, 12, 12, 12, 12, 12, -78).

Programs

Mathematica

coxG[{8,78,-12}] (* The coxG program is at A169452 *) (* Harvey P. Dale, May 26 2017 *)

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)/(78*t^8 - 12*t^7 - 12*t^6 - 12*t^5 - 12*t^4 - 12*t^3 - 12*t^2 - 12*t + 1).