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 A170679 Number of reduced words of length n in Coxeter group on 46 generators S_i with relations (S_i)^2 = (S_i S_j)^49 = I. 0
 1, 46, 2070, 93150, 4191750, 188628750, 8488293750, 381973218750, 17188794843750, 773495767968750, 34807309558593750, 1566328930136718750, 70484801856152343750, 3171816083526855468750, 142731723758708496093750 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 COMMENTS The initial terms coincide with those of A170765, although the two sequences are eventually different. First disagreement is at index 49, the difference is 1035. - Klaus Brockhaus, Jun 14 2011 Computed with MAGMA using commands similar to those used to compute A154638. LINKS FORMULA G.f.: (t^49 + 2*t^48 + 2*t^47 + 2*t^46 + 2*t^45 + 2*t^44 + 2*t^43 + 2*t^42 + 2*t^41 + 2*t^40 + 2*t^39 + 2*t^38 + 2*t^37 + 2*t^36 + 2*t^35 + 2*t^34 + 2*t^33 + 2*t^32 + 2*t^31 + 2*t^30 + 2*t^29 + 2*t^28 + 2*t^27 + 2*t^26 + 2*t^25 + 2*t^24 + 2*t^23 + 2*t^22 + 2*t^21 + 2*t^20 + 2*t^19 + 2*t^18 + 2*t^17 + 2*t^16 + 2*t^15 + 2*t^14 + 2*t^13 + 2*t^12 + 2*t^11 + 2*t^10 + 2*t^9 + 2*t^8 + 2*t^7 + 2*t^6 + 2*t^5 + 2*t^4 + 2*t^3 + 2*t^2 + 2*t + 1)/(990*t^49 - 44*t^48 - 44*t^47 - 44*t^46 - 44*t^45 - 44*t^44 - 44*t^43 - 44*t^42 - 44*t^41 - 44*t^40 - 44*t^39 - 44*t^38 - 44*t^37 - 44*t^36 - 44*t^35 - 44*t^34 - 44*t^33 - 44*t^32 - 44*t^31 - 44*t^30 - 44*t^29 - 44*t^28 - 44*t^27 - 44*t^26 - 44*t^25 - 44*t^24 - 44*t^23 - 44*t^22 - 44*t^21 - 44*t^20 - 44*t^19 - 44*t^18 - 44*t^17 - 44*t^16 - 44*t^15 - 44*t^14 - 44*t^13 - 44*t^12 - 44*t^11 - 44*t^10 - 44*t^9 - 44*t^8 - 44*t^7 - 44*t^6 - 44*t^5 - 44*t^4 - 44*t^3 - 44*t^2 - 44*t + 1). MATHEMATICA With[{num=Total[2t^Range[48]]+t^49+1, den=Total[-44 t^Range[48]]+1+ 990t^49}, CoefficientList[Series[num/den, {t, 0, 21}], t]] (* From Harvey P. Dale, June 14 2011 *) CROSSREFS Cf. A170765 (G.f.: (1+x)/(1-45*x). Sequence in context: A170583 A170631 * A170727 A170765 A218748 A158752 Adjacent sequences:  A170676 A170677 A170678 * A170680 A170681 A170682 KEYWORD nonn,easy AUTHOR John Cannon (john(AT)maths.usyd.edu.au) and N. J. A. Sloane, Dec 03 2009 STATUS approved

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