A162756 Number of reduced words of length n in Coxeter group on 10 generators S_i with relations (S_i)^2 = (S_i S_j)^3 = I.

1, 10, 90, 765, 6480, 54720, 462060, 3900960, 32934240, 278047440, 2347418880, 19818097920, 167314426560, 1412553116160, 11925488816640, 100681016106240, 850000127201280, 7176131549061120, 60584536830274560, 511485342455439360

Offset: 0

Author

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

Keywords

• nonn

Comments

The initial terms coincide with those of A003952, 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 (8, 8, -36).

Formula

G.f.: (t^3 + 2*t^2 + 2*t + 1)/(36*t^3 - 8*t^2 - 8*t + 1)