cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

Previous Showing 11-20 of 58 results. Next

A163347 Number of reduced words of length n in Coxeter group on 8 generators S_i with relations (S_i)^2 = (S_i S_j)^5 = I.

Original entry on oeis.org

1, 8, 56, 392, 2744, 19180, 134064, 937104, 6550320, 45786384, 320044452, 2237094216, 15637173048, 109303031880, 764022547512, 5340478146444, 37329666414768, 260932440209616, 1823904280240560, 12748996716570576
Offset: 0

Views

Author

John Cannon and N. J. A. Sloane, Dec 03 2009

Keywords

Comments

The initial terms coincide with those of A003950, although the two sequences are eventually different.
Computed with MAGMA using commands similar to those used to compute A154638.

Programs

  • Magma
    R:=PowerSeriesRing(Integers(), 30); Coefficients(R!( (1+x)*(1-x^5)/(1-7*x+27*x^5-21*x^6) )); // G. C. Greubel, May 12 2019
    
  • Mathematica
    CoefficientList[Series[(1+x)*(1-x^5)/(1-7*x+27*x^5-21*x^6), {x, 0, 30}], x] (* or *) LinearRecurrence[{6,6,6,6,-21}, {1,8,56,392,2744,19180}, 30] (* G. C. Greubel, Dec 19 2016 *)
    coxG[{5, 21, -6}] (* The coxG program is at A169452 *) (* G. C. Greubel, May 12 2019 *)
  • PARI
    my(x='x+O('x^30)); Vec((1+x)*(1-x^5)/(1-7*x+27*x^5-21*x^6)) \\ G. C. Greubel, Dec 19 2016
    
  • Sage
    ((1+x)*(1-x^5)/(1-7*x+27*x^5-21*x^6)).series(x, 30).coefficients(x, sparse=False) # G. C. Greubel, May 12 2019

Formula

G.f.: (t^5 + 2*t^4 + 2*t^3 + 2*t^2 + 2*t + 1)/(21*t^5 - 6*t^4 - 6*t^3 - 6*t^2 - 6*t + 1).
a(n) = 6*a(n-1)+6*a(n-2)+6*a(n-3)+6*a(n-4)-21*a(n-5). - Wesley Ivan Hurt, May 10 2021

A163924 Number of reduced words of length n in Coxeter group on 8 generators S_i with relations (S_i)^2 = (S_i S_j)^6 = I.

Original entry on oeis.org

1, 8, 56, 392, 2744, 19208, 134428, 940800, 6584256, 46080384, 322496832, 2257016832, 15795891636, 110548662840, 773682621768, 5414672451384, 37894967433288, 265210605012024, 1856095143363468, 12990012903371952
Offset: 0

Views

Author

John Cannon and N. J. A. Sloane, Dec 03 2009

Keywords

Comments

The initial terms coincide with those of A003950, although the two sequences are eventually different.
Computed with MAGMA using commands similar to those used to compute A154638.

Programs

  • GAP
    a:=[8,56,392,2744,19208,134428];; for n in [7..30] do a[n]:=6*(a[n-1] +a[n-2]+a[n-3]+a[n-4]+a[n-5]) -21*a[n-6]; od; Concatenation([1], a); # G. C. Greubel, Aug 10 2019
  • Magma
    R:=PowerSeriesRing(Integers(), 30); Coefficients(R!( (1+t)*(1-t^6)/(1-7*t+27*t^6-21*t^7) )); // G. C. Greubel, Aug 10 2019
    
  • Maple
    seq(coeff(series((1+t)*(1-t^6)/(1-7*t+27*t^6-21*t^7), t, n+1), t, n), n = 0 .. 30); # G. C. Greubel, Aug 10 2019
  • Mathematica
    coxG[{6,21,-6}] (* The coxG program is at A169452 *) (* Harvey P. Dale, Jan 24 2016 *)
    CoefficientList[Series[(1+t)*(1-t^6)/(1-7*t+27*t^6-21*t^7), {t,0,30}], t] (* G. C. Greubel, Aug 08 2017 *)
  • PARI
    my(t='t+O('t^30)); Vec((1+t)*(1-t^6)/(1-7*t+27*t^6-21*t^7)) \\ G. C. Greubel, Aug 08 2017
    
  • Sage
    def A163924_list(prec):
        P. = PowerSeriesRing(ZZ, prec)
        return P((1+t)*(1-t^6)/(1-7*t+27*t^6-21*t^7)).list()
    A163924_list(30) # G. C. Greubel, Aug 10 2019
    

Formula

G.f.: (t^6 + 2*t^5 + 2*t^4 + 2*t^3 + 2*t^2 + 2*t + 1)/(21*t^6 - 6*t^5 - 6*t^4 - 6*t^3 - 6*t^2 - 6*t + 1).
a(n) = -21*a(n-6) + 6*Sum_{k=1..5} a(n-k). - Wesley Ivan Hurt, May 11 2021

A164373 Number of reduced words of length n in Coxeter group on 8 generators S_i with relations (S_i)^2 = (S_i S_j)^7 = I.

Original entry on oeis.org

1, 8, 56, 392, 2744, 19208, 134456, 941164, 6587952, 46114320, 322790832, 2259469968, 15815828784, 110707574544, 774930433956, 5424354927432, 37969377752376, 265777897314888, 1860391054122552, 13022357800350024
Offset: 0

Views

Author

John Cannon and N. J. A. Sloane, Dec 03 2009

Keywords

Comments

The initial terms coincide with those of A003950, although the two sequences are eventually different.
Computed with MAGMA using commands similar to those used to compute A154638.

Programs

  • GAP
    a:=[8, 56, 392, 2744, 19208, 134456, 941164];; for n in [8..30] do a[n]:=6*(a[n-1] +a[n-2]+a[n-3]+a[n-4]+a[n-5]+a[n-6]) -21*a[n-7]; od; Concatenation([1], a); # G. C. Greubel, Aug 28 2019
  • Magma
    R:=PowerSeriesRing(Integers(), 30); Coefficients(R!( (1+t)*(1-t^7)/(1-7*t+27*t^7-21*t^8) )); // G. C. Greubel, Aug 28 2019
    
  • Maple
    seq(coeff(series((1+t)*(1-t^7)/(1-7*t+27*t^7-21*t^8), t, n+1), t, n), n = 0 .. 30); # G. C. Greubel, Aug 28 2019
  • Mathematica
    CoefficientList[Series[(1+t)*(1-t^7)/(1-7*t+27*t^7-21*t^8), {t, 0, 30}], t] (* G. C. Greubel, Sep 17 2017 *)
    coxG[{7, 21, -6}] (* The coxG program is at A169452 *) (* G. C. Greubel, Aug 28 2019 *)
  • PARI
    my(t='t+O('t^30)); Vec((1+t)*(1-t^7)/(1-7*t+27*t^7-21*t^8)) \\ G. C. Greubel, Sep 17 2017
    
  • Sage
    def A164373_list(prec):
        P. = PowerSeriesRing(ZZ, prec)
        return P((1+t)*(1-t^7)/(1-7*t+27*t^7-21*t^8)).list()
    A164373_list(30) # G. C. Greubel, Aug 28 2019
    

Formula

G.f.: (t^7 + 2*t^6 + 2*t^5 + 2*t^4 + 2*t^3 + 2*t^2 + 2*t + 1)/(21*t^7 - 6*t^6 - 6*t^5 - 6*t^4 - 6*t^3 - 6*t^2 - 6*t + 1).
a(n) = -21*a(n-7) + 6*Sum_{k=1..6} a(n-k). - Wesley Ivan Hurt, May 11 2021

A165786 Number of reduced words of length n in Coxeter group on 8 generators S_i with relations (S_i)^2 = (S_i S_j)^10 = I.

Original entry on oeis.org

1, 8, 56, 392, 2744, 19208, 134456, 941192, 6588344, 46118408, 322828828, 2259801600, 15818609856, 110730259584, 775111751232, 5425781797632, 37980469356480, 265863262906752, 1861042682227008, 13027297668747264
Offset: 0

Views

Author

John Cannon and N. J. A. Sloane, Dec 03 2009

Keywords

Comments

The initial terms coincide with those of A003950, although the two sequences are eventually different.
Computed with MAGMA using commands similar to those used to compute A154638.

Programs

  • GAP
    a:=[8, 56, 392, 2744, 19208, 134456, 941192, 6588344, 46118408, 322828828];; for n in [11..20] do a[n]:=6*Sum([1..9], j-> a[n-j]) -21*a[n-10]; od; Concatenation([1], a); # G. C. Greubel, Sep 22 2019
  • Magma
    R:=PowerSeriesRing(Integers(), 20); Coefficients(R!( (1+t)*(1-t^10)/(1-7*t+27*t^10-21*t^11) )); // G. C. Greubel, Sep 22 2019
    
  • Maple
    seq(coeff(series((1+t)*(1-t^10)/(1-7*t+27*t^10-21*t^11), t, n+1), t, n), n = 0..20); # G. C. Greubel, Sep 22 2019
  • Mathematica
    With[{num=Total[2t^Range[9]]+t^10+1,den=Total[-6 t^Range[9]]+21t^10+1}, CoefficientList[Series[num/den,{t,0,30}],t]] (* Harvey P. Dale, Oct 20 2011 *)
    CoefficientList[Series[(1+t)*(1-t^10)/(1-7*t+27*t^10-21*t^11), {t,0,20}], t] (* or *) coxG[{10, 21, -6}] (* The coxG program is at A169452 *) (* G. C. Greubel, Sep 22 2019 *)
  • PARI
    my(t='t+O('t^20)); Vec((1+t)*(1-t^10)/(1-7*t+27*t^10-21*t^11)) \\ G. C. Greubel, Sep 22 2019
    
  • Sage
    def A165786_list(prec):
        P. = PowerSeriesRing(ZZ, prec)
        return P( (1+t)*(1-t^10)/(1-7*t+27*t^10-21*t^11) ).list()
    A165786_list(30) # G. C. Greubel, Sep 22 2019
    

Formula

G.f.: (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)/(21*t^10 - 6*t^9 - 6*t^8 - 6*t^7 - 6*t^6 - 6*t^5 - 6*t^4 - 6*t^3 - 6*t^2 - 6*t + 1).

A166366 Number of reduced words of length n in Coxeter group on 8 generators S_i with relations (S_i)^2 = (S_i S_j)^11 = I.

Original entry on oeis.org

1, 8, 56, 392, 2744, 19208, 134456, 941192, 6588344, 46118408, 322828856, 2259801964, 15818613552, 110730293520, 775112045232, 5425784250768, 37980489294384, 265863421833744, 1861043930247600, 13027307353612944
Offset: 0

Views

Author

John Cannon and N. J. A. Sloane, Dec 03 2009

Keywords

Comments

The initial terms coincide with those of A003950, although the two sequences are eventually different.
Computed with MAGMA using commands similar to those used to compute A154638.

Programs

  • Maple
    seq(coeff(series((1+t)*(1-t^11)/(1-7*t+27*t^11-21*t^12), t, n+1), t, n), n = 0 .. 30); # G. C. Greubel, Mar 13 2020
  • Mathematica
    CoefficientList[Series[(1+t)*(1-t^11)/(1-7*t+27*t^11-21*t^12), {t,0,30}], t] (* G. C. Greubel, May 10 2016 *)
    coxG[{11, 21, -6}] (* The coxG program is in A169452 *) (* G. C. Greubel, Mar 13 2020 *)
  • Sage
    def A166366_list(prec):
        P. = PowerSeriesRing(ZZ, prec)
        return P( (1+t)*(1-t^11)/(1-7*t+27*t^11-21*t^12) ).list()
    A166366_list(30) # G. C. Greubel, Mar 13 2020

Formula

G.f.: (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)/(21*t^11 - 6*t^10 - 6*t^9 - 6*t^8 - 6*t^7 - 6*t^6 - 6*t^5 - 6*t^4 - 6*t^3 - 6*t^2 - 6*t + 1).

A166538 Number of reduced words of length n in Coxeter group on 8 generators S_i with relations (S_i)^2 = (S_i S_j)^12 = I.

Original entry on oeis.org

1, 8, 56, 392, 2744, 19208, 134456, 941192, 6588344, 46118408, 322828856, 2259801992, 15818613916, 110730297216, 775112079168, 5425784544768, 37980491747520, 265863441771648, 1861044089174592, 13027308601633536
Offset: 0

Views

Author

John Cannon and N. J. A. Sloane, Dec 03 2009

Keywords

Comments

The initial terms coincide with those of A003950, although the two sequences are eventually different.
Computed with MAGMA using commands similar to those used to compute A154638.

Crossrefs

Programs

  • Magma
    R:=PowerSeriesRing(Integers(), 30); Coefficients(R!( (1+x)*(1-x^12)/(1-7*x+27*x^12-21*x^13) )); // G. C. Greubel, Aug 23 2024
    
  • Mathematica
    CoefficientList[Series[(1+t)*(1-t^12)/(1-7*t+27*t^12-21*t^13), {t, 0, 50}], t] (* G. C. Greubel, May 16 2016; Aug 23 2024 *)
    coxG[{12,21,-6}] (* The coxG program is at A169452 *) (* Harvey P. Dale, Oct 24 2016 *)
  • SageMath
    def A166538_list(prec):
        P. = PowerSeriesRing(ZZ, prec)
        return P( (1+x)*(1-x^12)/(1-7*x+27*x^12-21*x^13) ).list()
    A166538_list(30) # G. C. Greubel, Aug 23 2024

Formula

G.f.: (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)/(21*t^12 - 6*t^11 - 6*t^10 - 6*t^9 - 6*t^8 - 6*t^7 - 6*t^6 - 6*t^5 - 6*t^4 - 6*t^3 - 6*t^2 - 6*t + 1).
From G. C. Greubel, Aug 23 2024: (Start)
a(n) = 6*Sum_{j=1..11} a(n-j) - 21*a(n-12).
G.f.: (1 + x)*(1 - x^12)/(1 - 7*x + 27*x^12 - 21*x^13). (End)

A166910 Number of reduced words of length n in Coxeter group on 8 generators S_i with relations (S_i)^2 = (S_i S_j)^13 = I.

Original entry on oeis.org

1, 8, 56, 392, 2744, 19208, 134456, 941192, 6588344, 46118408, 322828856, 2259801992, 15818613944, 110730297580, 775112082864, 5425784578704, 37980492041520, 265863444224784, 1861044109112496, 13027308760560528
Offset: 0

Views

Author

John Cannon and N. J. A. Sloane, Dec 03 2009

Keywords

Comments

The initial terms coincide with those of A003950, although the two sequences are eventually different.
Computed with MAGMA using commands similar to those used to compute A154638.

Programs

  • Mathematica
    CoefficientList[Series[(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)/(21*t^13 - 6*t^12 - 6*t^11 - 6*t^10 - 6*t^9 - 6*t^8 - 6*t^7 - 6*t^6 - 6*t^5 - 6*t^4 - 6*t^3 - 6*t^2 - 6*t + 1), {t, 0, 50}], t] (* G. C. Greubel, May 28 2016 *)
    coxG[{13,21,-6}] (* The coxG program is at A169452 *) (* Harvey P. Dale, Jul 05 2021 *)

Formula

G.f.: (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)/(21*t^13 - 6*t^12 - 6*t^11 - 6*t^10 - 6*t^9 - 6*t^8 - 6*t^7 - 6*t^6 - 6*t^5 - 6*t^4 - 6*t^3 - 6*t^2 - 6*t + 1).

A167109 Number of reduced words of length n in Coxeter group on 8 generators S_i with relations (S_i)^2 = (S_i S_j)^14 = I.

Original entry on oeis.org

1, 8, 56, 392, 2744, 19208, 134456, 941192, 6588344, 46118408, 322828856, 2259801992, 15818613944, 110730297608, 775112083228, 5425784582400, 37980492075456, 265863444518784, 1861044111565632, 13027308780498432
Offset: 0

Views

Author

John Cannon and N. J. A. Sloane, Dec 03 2009

Keywords

Comments

The initial terms coincide with those of A003950, although the two sequences are eventually different.
Computed with MAGMA using commands similar to those used to compute A154638.

Programs

  • Mathematica
    With[{num=Total[2t^Range[13]]+t^14+1,den=Total[-6 t^Range[13]]+ 21t^14+1}, CoefficientList[Series[num/den,{t,0,30}],t]] (* Harvey P. Dale, Jul 15 2011 *)
    CoefficientList[Series[(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)/ (21*t^14 - 6*t^13 - 6*t^12 - 6*t^11 - 6*t^10 - 6*t^9 - 6*t^8 - 6*t^7 - 6*t^6 - 6*t^5 - 6*t^4 - 6*t^3 - 6*t^2 - 6*t + 1), {t, 0, 50}], t] (* G. C. Greubel, Jun 03 2016 *)

Formula

G.f.: (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)/(21*t^14 - 6*t^13 - 6*t^12 - 6*t^11 - 6*t^10 - 6*t^9 - 6*t^8 - 6*t^7 - 6*t^6 - 6*t^5 - 6*t^4 - 6*t^3 - 6*t^2 - 6*t + 1).

A167653 Number of reduced words of length n in Coxeter group on 8 generators S_i with relations (S_i)^2 = (S_i S_j)^15 = I.

Original entry on oeis.org

1, 8, 56, 392, 2744, 19208, 134456, 941192, 6588344, 46118408, 322828856, 2259801992, 15818613944, 110730297608, 775112083256, 5425784582764, 37980492079152, 265863444552720, 1861044111859632, 13027308782951568
Offset: 0

Views

Author

John Cannon and N. J. A. Sloane, Dec 03 2009

Keywords

Comments

The initial terms coincide with those of A003950, although the two sequences are eventually different.
Computed with MAGMA using commands similar to those used to compute A154638.

Programs

  • Mathematica
    CoefficientList[Series[(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)/(21*t^15 - 6*t^14 - 6*t^13 - 6*t^12 - 6*t^11 - 6*t^10 - 6*t^9 - 6*t^8 - 6*t^7 - 6*t^6 - 6*t^5 - 6*t^4 - 6*t^3 - 6*t^2 - 6*t + 1), {t, 0, 50}], t] (* G. C. Greubel, Jun 18 2016 *)

Formula

G.f.: (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)/(21*t^15 - 6*t^14 - 6*t^13 - 6*t^12 - 6*t^11 - 6*t^10 - 6*t^9 - 6*t^8 - 6*t^7 - 6*t^6 - 6*t^5 - 6*t^4 - 6*t^3 - 6*t^2 - 6*t + 1).

A167899 Number of reduced words of length n in Coxeter group on 8 generators S_i with relations (S_i)^2 = (S_i S_j)^16 = I.

Original entry on oeis.org

1, 8, 56, 392, 2744, 19208, 134456, 941192, 6588344, 46118408, 322828856, 2259801992, 15818613944, 110730297608, 775112083256, 5425784582792, 37980492079516, 265863444556416, 1861044111893568, 13027308783245568
Offset: 0

Views

Author

John Cannon and N. J. A. Sloane, Dec 03 2009

Keywords

Comments

The initial terms coincide with those of A003950, although the two sequences are eventually different.
Computed with MAGMA using commands similar to those used to compute A154638.

Programs

  • Mathematica
    CoefficientList[Series[(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)/(21*t^16 - 6*t^15 - 6*t^14 - 6*t^13 - 6*t^12 - 6*t^11 - 6*t^10 - 6*t^9 - 6*t^8 - 6*t^7 - 6*t^6 - 6*t^5 - 6*t^4 - 6*t^3 - 6*t^2 - 6*t + 1), {t, 0, 50}], t] (* G. C. Greubel, Jul 01 2016 *)

Formula

G.f.: (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)/( 21*t^16 - 6*t^15 - 6*t^14 - 6*t^13 - 6*t^12 - 6*t^11 - 6*t^10 - 6*t^9 - 6*t^8 - 6*t^7 - 6*t^6 - 6*t^5 - 6*t^4 - 6*t^3 - 6*t^2 - 6*t + 1).
Previous Showing 11-20 of 58 results. Next