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A164694 Number of reduced words of length n in Coxeter group on 49 generators S_i with relations (S_i)^2 = (S_i S_j)^7 = I. 0
1, 49, 2352, 112896, 5419008, 260112384, 12485394432, 599298931560, 28766348658432, 1380784732896408, 66277667049027840, 3181328012113348608, 152703744281921323008, 7329779711155291815936, 351829425445361287501224 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

The initial terms coincide with those of A170768, 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..14.

Index entries for linear recurrences with constant coefficients, signature (47, 47, 47, 47, 47, 47, -1128).

FORMULA

G.f. (t^7 + 2*t^6 + 2*t^5 + 2*t^4 + 2*t^3 + 2*t^2 + 2*t + 1)/(1128*t^7 - 47*t^6 -

47*t^5 - 47*t^4 - 47*t^3 - 47*t^2 - 47*t + 1)

CROSSREFS

Sequence in context: A163287 A163835 A164350 * A165181 A165709 A166324

Adjacent sequences:  A164691 A164692 A164693 * A164695 A164696 A164697

KEYWORD

nonn

AUTHOR

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

STATUS

approved

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Last modified May 11 00:21 EDT 2021. Contains 343784 sequences. (Running on oeis4.)