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A163090
Number of reduced words of length n in Coxeter group on 14 generators S_i with relations (S_i)^2 = (S_i S_j)^4 = I.
0
1, 14, 182, 2366, 30667, 397488, 5152056, 66777984, 865538310, 11218616136, 145409328792, 1884713116104, 24428580744204, 316629386210592, 4103970233205024, 53193330778861728, 689461735481280216, 8936411345795737440, 115828687266480560736, 1501305644372339725920
OFFSET
0,2
COMMENTS
The initial terms coincide with those of A170733, although the two sequences are eventually different.
Computed with MAGMA using commands similar to those used to compute A154638.
FORMULA
G.f.: (t^4 + 2*t^3 + 2*t^2 + 2*t + 1)/(78*t^4 - 12*t^3 - 12*t^2 - 12*t + 1).
MATHEMATICA
CoefficientList[ Series[(t^4 + 2 t^3 + 2 t^2 + 2 t + 1)/(78 t^4 - 12 t^3 - 12 t^2 - 12 t + 1), {t, 0, 20}], t] (* Jinyuan Wang, Mar 22 2020 *)
CROSSREFS
Sequence in context: A097828 A030008 A342883 * A163439 A163959 A164618
KEYWORD
nonn
AUTHOR
John Cannon and N. J. A. Sloane, Dec 03 2009
EXTENSIONS
More terms from Jinyuan Wang, Mar 22 2020
STATUS
approved