The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation. Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A163432 Number of reduced words of length n in Coxeter group on 12 generators S_i with relations (S_i)^2 = (S_i S_j)^5 = I. 1
 1, 12, 132, 1452, 15972, 175626, 1931160, 21234840, 233496120, 2567499000, 28231951770, 310435603500, 3413517587700, 37534684133100, 412727480315700, 4538308419052650, 49902767052699000, 548725632894681000 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 COMMENTS The initial terms coincide with those of A003954, although the two sequences are eventually different. Computed with MAGMA using commands similar to those used to compute A154638. LINKS G. C. Greubel, Table of n, a(n) for n = 0..950 Index entries for linear recurrences with constant coefficients, signature (10, 10, 10, 10, -55). FORMULA G.f.: (t^5 + 2*t^4 + 2*t^3 + 2*t^2 + 2*t + 1)/(55*t^5 - 10*t^4 - 10*t^3 - 10*t^2 - 10*t + 1). a(n) = 10*a(n-1)+10*a(n-2)+10*a(n-3)+10*a(n-4)-55*a(n-5). - Wesley Ivan Hurt, May 10 2021 MATHEMATICA CoefficientList[Series[(1+x)*(1-x^5)/(1-11*x+65*x^5-55*x^6), {x, 0, 30}], x] (* or *) LinearRecurrence[{10, 10, 10, 10, -55}, {1, 12, 132, 1452, 15972, 175626}, 30] (* G. C. Greubel, Dec 23 2016 *) coxG[{5, 55, -10}] (* The coxG program is at A169452 *) (* G. C. Greubel, May 12 2019 *) PROG (PARI) my(x='x+O('x^30)); Vec((1+x)*(1-x^5)/(1-11*x+65*x^5-55*x^6)) \\ G. C. Greubel, Dec 23 2016 (MAGMA) R:=PowerSeriesRing(Integers(), 30); Coefficients(R!( (1+x)*(1-x^5)/(1-11*x+65*x^5-55*x^6) )); // G. C. Greubel, May 12 2019 (Sage) ((1+x)*(1-x^5)/(1-11*x+65*x^5-55*x^6)).series(x, 30).coefficients(x, sparse=False) # G. C. Greubel, May 12 2019 CROSSREFS Sequence in context: A010580 A010577 A163055 * A163957 A063813 A164601 Adjacent sequences:  A163429 A163430 A163431 * A163433 A163434 A163435 KEYWORD nonn AUTHOR John Cannon and N. J. A. Sloane, Dec 03 2009 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified October 26 02:14 EDT 2021. Contains 348256 sequences. (Running on oeis4.)