# Greetings from The On-Line Encyclopedia of Integer Sequences! http://oeis.org/ Search: id:a164630 Showing 1-1 of 1 %I A164630 #11 Feb 22 2024 13:33:07 %S A164630 1,18,306,5202,88434,1503378,25557426,434476089,7386090912, %T A164630 125563501440,2134578775392,36287826447168,616892833115424, %U A164630 10487174482692864,178281903641223096,3030791298303722112,51523433990019421056 %N A164630 Number of reduced words of length n in Coxeter group on 18 generators S_i with relations (S_i)^2 = (S_i S_j)^7 = I. %C A164630 The initial terms coincide with those of A170737, although the two sequences are eventually different. %C A164630 Computed with MAGMA using commands similar to those used to compute A154638. %H A164630 Index entries for linear recurrences with constant coefficients, signature (16,16,16,16,16,16,-136). %F A164630 G.f.: (t^7 + 2*t^6 + 2*t^5 + 2*t^4 + 2*t^3 + 2*t^2 + 2*t + 1)/(136*t^7 - 16*t^6 -16*t^5 - 16*t^4 - 16*t^3 - 16*t^2 - 16*t + 1). %t A164630 coxG[{7,136,-16}] (* The coxG program is at A169452 *) (* _Harvey P. Dale_, Jan 17 2023 *) %K A164630 nonn %O A164630 0,2 %A A164630 _John Cannon_ and _N. J. A. Sloane_, Dec 03 2009 # Content is available under The OEIS End-User License Agreement: http://oeis.org/LICENSE