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 A163110 Number of reduced words of length n in Coxeter group on 19 generators S_i with relations (S_i)^2 = (S_i S_j)^4 = I. 0
 1, 19, 342, 6156, 110637, 1988388, 35735751, 642249324, 11542621410, 207446086881, 3728258709552, 67004941956759, 1204224973728534, 21642549713419572, 388963830112221249, 6990528525469894908, 125635046969043641691, 2257935858412484688900, 40580032910411799982386 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 COMMENTS The initial terms coincide with those of A170738, 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..18. Index entries for linear recurrences with constant coefficients, signature (17,17,17,-153). FORMULA G.f.: (t^4 + 2*t^3 + 2*t^2 + 2*t + 1)/(153*t^4 - 17*t^3 - 17*t^2 - 17*t + 1). MATHEMATICA coxG[{4, 153, -17}] (* The coxG program is at A169452 *) (* Harvey P. Dale, Aug 24 2019 *) PROG (PARI) Vec((t^4 + 2*t^3 + 2*t^2 + 2*t + 1)/(153*t^4 - 17*t^3 - 17*t^2 - 17*t + 1) + O(t^20)) \\ Jinyuan Wang, Mar 23 2020 CROSSREFS Sequence in context: A049629 A162805 A049664 * A163453 A163968 A164631 Adjacent sequences: A163107 A163108 A163109 * A163111 A163112 A163113 KEYWORD nonn AUTHOR John Cannon and N. J. A. Sloane, Dec 03 2009 EXTENSIONS More terms from Jinyuan Wang, Mar 23 2020 STATUS approved

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Last modified March 4 16:44 EST 2024. Contains 370532 sequences. (Running on oeis4.)