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A164674
Number of reduced words of length n in Coxeter group on 38 generators S_i with relations (S_i)^2 = (S_i S_j)^7 = I.
0
1, 38, 1406, 52022, 1924814, 71218118, 2635070366, 97497602839, 3607411279032, 133474216362480, 4938545969828712, 182726199567089568, 6760869335269121304, 250152163602569357904, 9255629986606705913226
OFFSET
0,2
COMMENTS
The initial terms coincide with those of A170757, although the two sequences are eventually different.
Computed with MAGMA using commands similar to those used to compute A154638.
FORMULA
G.f. (t^7 + 2*t^6 + 2*t^5 + 2*t^4 + 2*t^3 + 2*t^2 + 2*t + 1)/(666*t^7 - 36*t^6 -
36*t^5 - 36*t^4 - 36*t^3 - 36*t^2 - 36*t + 1)
CROSSREFS
Sequence in context: A163221 A163660 A164071 * A165170 A165687 A166170
KEYWORD
nonn
AUTHOR
John Cannon and N. J. A. Sloane, Dec 03 2009
STATUS
approved