A162831 Number of reduced words of length n in Coxeter group on 29 generators S_i with relations (S_i)^2 = (S_i S_j)^3 = I.

1, 29, 812, 22330, 613872, 16870518, 463637790, 12741680700, 350166543426, 9623266966782, 264466349471016, 7268056690405518, 199740527163222822, 5489263483947921132, 150855782871027600954, 4145814332316640869606

Offset: 0

Author

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

Keywords

• nonn

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.

Links

• Index entries for linear recurrences with constant coefficients, signature (27, 27, -378).

Programs

Mathematica

coxG[{3,378,-27}] (* The coxG program is at A169452 *) (* Harvey P. Dale, May 20 2018 *)

Formula

G.f.: (t^3 + 2*t^2 + 2*t + 1)/(378*t^3 - 27*t^2 - 27*t + 1)