A162811 Number of reduced words of length n in Coxeter group on 25 generators S_i with relations (S_i)^2 = (S_i S_j)^3 = I.

1, 25, 600, 14100, 331200, 7776300, 182580900, 4286804400, 100649603100, 2363145044100, 55484118871200, 1302707779596300, 30586185632580900, 718130931671624400, 16860946350828143100, 395876990262902324100

Offset: 0

Author

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

Keywords

• nonn

Comments

The initial terms coincide with those of A170744, 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 (23, 23, -276).

Programs

Mathematica

coxG[{3,276,-23}] (* The coxG program is at A169452 *) (* Harvey P. Dale, Sep 10 2021 *)

Formula

G.f.: (t^3 + 2*t^2 + 2*t + 1)/(276*t^3 - 23*t^2 - 23*t + 1)