A162836 Number of reduced words of length n in Coxeter group on 32 generators S_i with relations (S_i)^2 = (S_i S_j)^3 = I.

1, 32, 992, 30256, 922560, 28123200, 857303760, 26133818400, 796656376800, 24285059607600, 740299253976000, 22567084192296000, 687928950670626000, 20970641892788820000, 639263431154365740000, 19487135229352795710000

Offset

0,2

Comments

The initial terms coincide with those of A170751, although the two sequences are eventually different.

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

Links

Table of n, a(n) for n=0..15.

Index entries for linear recurrences with constant coefficients, signature (30, 30, -465).

Formula

G.f.: (t^3 + 2*t^2 + 2*t + 1)/(465*t^3 - 30*t^2 - 30*t + 1)

Crossrefs

Sequence in context: A282313 A264344 A228983 * A163215 A163565 A164036

Adjacent sequences: A162833 A162834 A162835 * A162837 A162838 A162839

Keyword

nonn

Author

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

Status

approved