A164693 Number of reduced words of length n in Coxeter group on 48 generators S_i with relations (S_i)^2 = (S_i S_j)^7 = I.

1, 48, 2256, 106032, 4983504, 234224688, 11008560336, 517402334664, 24317909676192, 1142941752290400, 53718262240589472, 2524758319805916768, 118663640772294032544, 5577191104144368918624, 262127981323573161732216

Offset: 0

Author

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

Keywords

• nonn

Comments

The initial terms coincide with those of A170767, 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 (46, 46, 46, 46, 46, 46, -1081).

Programs

Mathematica

coxG[{7,1081,-46}] (* The coxG program is at A169452 *) (* Harvey P. Dale, Dec 10 2024 *)

Formula

G.f.: (t^7 + 2*t^6 + 2*t^5 + 2*t^4 + 2*t^3 + 2*t^2 + 2*t + 1)/(1081*t^7 - 46*t^6 - 46*t^5 - 46*t^4 - 46*t^3 - 46*t^2 - 46*t + 1).