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.

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A098172 Triangle T(n,k) with diagonals T(n,n-k) = binomial(n,3k).

Original entry on oeis.org

1, 0, 1, 0, 0, 1, 0, 0, 1, 1, 0, 0, 0, 4, 1, 0, 0, 0, 0, 10, 1, 0, 0, 0, 0, 1, 20, 1, 0, 0, 0, 0, 0, 7, 35, 1, 0, 0, 0, 0, 0, 0, 28, 56, 1, 0, 0, 0, 0, 0, 0, 1, 84, 84, 1, 0, 0, 0, 0, 0, 0, 0, 10, 210, 120, 1, 0, 0, 0, 0, 0, 0, 0, 0, 55, 462, 165, 1, 0, 0, 0, 0, 0, 0, 0, 0, 1, 220, 924, 220, 1
Offset: 0

Views

Author

Paul Barry, Aug 30 2004

Keywords

Comments

Row sums are A024493.
From R. J. Mathar, Mar 22 2013: (Start)
The matrix inverse starts
1;
0, 1;
0, 0, 1;
0, 0, -1, 1;
0, 0, 4, -4, 1;
0, 0, -40, 40, -10, 1;
0, 0, 796, -796, 199, -20, 1;
0, 0, -27580, 27580, -6895, 693, -35, 1;
... (End)

Examples

			Rows begin
  {1},
  {0,1},
  {0,0,1},
  {0,0,1,1},
  {0,0,0,4,1},
  {0,0,0,0,10,1},
  ...
		

Crossrefs

Cf. A098158.

Programs

  • GAP
    Flat(List([0..12], n-> List([0..n], k-> Binomial(n, 3*(n-k)) ))); # G. C. Greubel, Mar 15 2019
  • Magma
    [[Binomial(n, 3*(n-k)): k in [0..n]]: n in [0..12]]; // G. C. Greubel, Mar 15 2019
    
  • Mathematica
    Table[Binomial[n, 3(n-k)], {n, 0, 12}, {k, 0, n}]//Flatten (* G. C. Greubel, Mar 15 2019 *)
  • PARI
    {T(n, k) = binomial(n, 3*(n-k))}; \\ G. C. Greubel, Mar 15 2019
    
  • Sage
    [[binomial(n, 3*(n-k)) for k in (0..n)] for n in (0..12)] # G. C. Greubel, Mar 15 2019
    

Formula

Triangle T(n, k) = binomial(n, 3(n-k)).

A152262 a(n) = 14*a(n-1) - 43*a(n-2), n > 1; a(0)=1, a(1)=7.

Original entry on oeis.org

1, 7, 55, 469, 4201, 38647, 360415, 3383989, 31878001, 300780487, 2840172775, 26828857909, 253476581401, 2395031249527, 22630944493135, 213846879174229, 2020725695234401, 19094743928789767, 180435210107977495
Offset: 0

Views

Author

Al Hakanson (hawkuu(AT)gmail.com), Dec 01 2008

Keywords

Comments

Binomial transform of A145301. Inverse binomial transform of A152263. - Philippe Deléham, Dec 03 2008

Crossrefs

Programs

  • Magma
    Z:= PolynomialRing(Integers()); N:=NumberField(x^2-6); S:=[ ((7+r6)^n+(7-r6)^n)/2: n in [0..18] ]; [ Integers()!S[j]: j in [1..#S] ]; // Klaus Brockhaus, Dec 03 2008
    
  • Magma
    [n le 2 select 7^(n-1) else 14*Self(n-1) -43*Self(n-2): n in [1..30]]; // G. C. Greubel, May 23 2023
    
  • Mathematica
    LinearRecurrence[{14,-43},{1,7},30] (* Harvey P. Dale, Apr 26 2015 *)
  • SageMath
    @CachedFunction
    def a(n): # a = A152262
        if (n<2): return 7^n
        else: return 14*a(n-1) - 43*a(n-2)
    [a(n) for n in range(41)] # G. C. Greubel, May 23 2023

Formula

a(n) = ((7 + sqrt(6))^n + (7 - sqrt(6))^n)/2.
From Philippe Deléham, Dec 03 2008: (Start)
G.f.: (1-7*x)/(1-14*x+43*x^2).
a(n) = Sum_{k=0..n} A098158(n,k)*7^(2k-n)*6^(n-k). (End)
a(n) = Sum_{k=0..n} A027907(n,2k)*6^k. - J. Conrad, Aug 24 2016
E.g.f.: cosh(sqrt(6)*x)*exp(7*x). - Ilya Gutkovskiy, Aug 24 2016
a(n) = m^n*(ChebyshevU(n, 7/m) - (7/m)*ChebyshevU(n-1, 7/m)), with m = sqrt(43). - G. C. Greubel, May 23 2023

Extensions

Name from Philippe Deléham, Dec 03 2008

A098173 Triangle T(n,k) with diagonals T(n,n-k) = binomial(n, 4k).

Original entry on oeis.org

1, 0, 1, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 1, 0, 0, 0, 0, 5, 1, 0, 0, 0, 0, 0, 15, 1, 0, 0, 0, 0, 0, 0, 35, 1, 0, 0, 0, 0, 0, 0, 1, 70, 1, 0, 0, 0, 0, 0, 0, 0, 9, 126, 1, 0, 0, 0, 0, 0, 0, 0, 0, 45, 210, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 165, 330, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 495, 495, 1
Offset: 0

Views

Author

Paul Barry, Aug 30 2004

Keywords

Comments

Row sums are A038503.

Examples

			Rows begin
  {1},
  {0,1},
  {0,0,1},
  {0,0,0,1},
  {0,0,0,1,1},
  {0,0,0,0,5,1},
  ...
		

Crossrefs

Programs

  • GAP
    Flat(List([0..12], n-> List([0..n], k-> Binomial(n, 4*(n-k)) ))); # G. C. Greubel, Mar 15 2019
  • Magma
    [[Binomial(n, 4*(n-k)): k in [0..n]]: n in [0..12]]; // G. C. Greubel, Mar 15 2019
    
  • Mathematica
    Table[Binomial[n, 4(n-k)], {n, 0, 12}, {k, 0, n}]//Flatten (* G. C. Greubel, Mar 15 2019 *)
  • PARI
    {T(n, k) = binomial(n, 4*(n-k))}; \\ G. C. Greubel, Mar 15 2019
    
  • Sage
    [[binomial(n, 4*(n-k)) for k in (0..n)] for n in (0..12)] # G. C. Greubel, Mar 15 2019
    

Formula

Triangle T(n, k) = binomial(n, 4(n-k)).

A143647 a(n) = ((5 + sqrt(3))^n + (5 - sqrt(3))^n)/2.

Original entry on oeis.org

1, 5, 28, 170, 1084, 7100, 47152, 315320, 2115856, 14221520, 95666368, 643790240, 4333242304, 29169037760, 196359046912, 1321871638400, 8898817351936, 59906997474560, 403295993003008, 2715005985589760, 18277548009831424
Offset: 0

Views

Author

Al Hakanson (hawkuu(AT)gmail.com), Oct 27 2008

Keywords

Comments

Binomial transform of A083882. - R. J. Mathar, Nov 01 2008
Inverse binomial transform of A147961.

Crossrefs

Programs

  • Magma
    Z:= PolynomialRing(Integers()); N:=NumberField(x^2-3); S:=[ ((5+r3)^n+(5-r3)^n)/2: n in [0..20] ]; [ Integers()!S[j]: j in [1..#S] ]; // Klaus Brockhaus, Nov 01 2008
  • Mathematica
    Simplify[With[{c=Sqrt[3]},Table[((5+c)^n+(5-c)^n)/2,{n,0,25}]]] (* or *) LinearRecurrence[{10,-22},{1,5},25] (* Harvey P. Dale, Jun 04 2011 *)

Formula

From Philippe Deléham, Klaus Brockhaus and R. J. Mathar, Nov 01 2008: (Start)
a(n) = 10*a(n-1) - 22*a(n-2), a(0)=1, a(1)=5.
G.f.: (1-5x)/(1-10x+22*x^2). (End)
a(n) = (Sum_{k=0..n} A098158(n,k)*5^(2*k)*3^(n-k))/5^n. - Philippe Deléham, Nov 06 2008

Extensions

More terms from Klaus Brockhaus and R. J. Mathar, Nov 01 2008
Edited by Klaus Brockhaus, Jul 15 2009

A146962 a(n) = 10*a(n-1) - 19*a(n-2) with a(0)=1, a(1)=5.

Original entry on oeis.org

1, 5, 31, 215, 1561, 11525, 85591, 636935, 4743121, 35329445, 263175151, 1960492055, 14604592681, 108796577765, 810478516711, 6037650189575, 44977410078241, 335058747180485, 2496016680318271, 18594050606753495
Offset: 0

Views

Author

Al Hakanson (hawkuu(AT)gmail.com), Nov 03 2008

Keywords

Comments

Binomial transform of A143648.
Inverse binomial transform of A145301.

Crossrefs

Programs

  • GAP
    a:=[1,5];; for n in [3..30] do a[n]:=10*a[n-1]-19*a[n-2]; od; a; # G. C. Greubel, Jan 08 2020
  • Magma
    Z:= PolynomialRing(Integers()); N:=NumberField(x^2-6); S:=[ ((5+r6)^n+(5-r6)^n)/2: n in [0..19] ]; [ Integers()!S[j]: j in [1..#S] ]; // Klaus Brockhaus, Nov 05 2008
    
  • Maple
    seq(coeff(series((1-5*x)/(1-10*x+19*x^2), x, n+1), x, n), n = 0..30); # G. C. Greubel, Jan 08 2020
  • Mathematica
    LinearRecurrence[{10,-19},{1,5},30] (* Harvey P. Dale, Apr 27 2014 *)
    CoefficientList[Series[(1-5x)/(1-10x+19x^2), {x, 0, 30}], x] (* Vincenzo Librandi, Apr 28 2014 *)
  • PARI
    my(x='x+O('x^30)); Vec((1-5*x)/(1-10*x+19*x^2)) \\ G. C. Greubel, Jan 08 2020
    
  • Sage
    def A146962_list(prec):
        P. = PowerSeriesRing(ZZ, prec)
        return P( (1-5*x)/(1-10*x+19*x^2) ).list()
    A146962_list(30) # G. C. Greubel, Jan 08 2020
    

Formula

a(n) = ((5 + sqrt(6))^n + (5 - sqrt(6))^n)/2.
G.f.: (1-5*x)/(1-10*x+19*x^2). - Philippe Deléham and Klaus Brockhaus, Nov 05 2008
a(n) = (Sum_{k=0..n} A098158(n,k)*5^(2*k)*6^(n-k))/5^n. - Philippe Deléham, Nov 06 2008
E.g.f.: exp(5*x)*cosh(sqrt(6)*x). - G. C. Greubel, Jan 08 2020

Extensions

Extended beyond a(7) by Klaus Brockhaus, Nov 05 2008
Edited by Klaus Brockhaus, Jul 15 2009
Name from Philippe Deléham and Klaus Brockhaus, Nov 05 2008

A146964 a(n) = ((4 + sqrt(7))^n + (4 - sqrt(7))^n)/2.

Original entry on oeis.org

1, 4, 23, 148, 977, 6484, 43079, 286276, 1902497, 12643492, 84025463, 558412276, 3711069041, 24662841844, 163903113383, 1089259330468, 7238946623297, 48108239012164, 319715392487639, 2124748988791636, 14120553377944337
Offset: 0

Views

Author

Al Hakanson (hawkuu(AT)gmail.com), Nov 03 2008

Keywords

Comments

Binomial transform of A146963.
Inverse binomial transform of A146965.

Crossrefs

Programs

  • GAP
    a:=[1,4];; for n in [3..25] do a[n]:=8*a[n-1]-9*a[n-2]; od; a; # G. C. Greubel, Jan 08 2020
  • Magma
    Z:= PolynomialRing(Integers()); N:=NumberField(x^2-7); S:=[ ((4+r7)^n+(4-r7)^n)/2: n in [0..20] ]; [ Integers()!S[j]: j in [1..#S] ]; // Klaus Brockhaus, Nov 05 2008
    
  • Maple
    seq(coeff(series((1-4*x)/(1-8*x+9*x^2), x, n+1), x, n), n = 0..25); # G. C. Greubel, Jan 08 2020
  • Mathematica
    LinearRecurrence[{8,-9}, {1,4}, 25] (* G. C. Greubel, Jan 08 2020 *)
  • PARI
    my(x='x+O('x^25)); Vec((1-4*x)/(1-8*x+9*x^2)) \\ G. C. Greubel, Jan 08 2020
    
  • Sage
    def A146964_list(prec):
        P. = PowerSeriesRing(ZZ, prec)
        return P( (1-4*x)/(1-8*x+9*x^2) ).list()
    A146964_list(25) # G. C. Greubel, Jan 08 2020
    

Formula

From Philippe Deléham and Klaus Brockhaus, Nov 05 2008: (Start)
a(n) = 8*a(n-1) - 9*a(n-2) with a(0)=1, a(1)=4.
G.f.: (1-4*x)/(1-8*x+9*x^2). (End)
a(n) = (Sum_{k=0..n} A098158(n,k)*4^(2*k)*7^(n-k))/4^n. - Philippe Deléham, Nov 06 2008
E.g.f.: exp(4*x)*cosh(sqrt(7)*x). - G. C. Greubel, Jan 08 2020

Extensions

Extended beyond a(7) by Klaus Brockhaus, Nov 05 2008
Edited by Klaus Brockhaus, Jul 16 2009

A146965 a(n) = 10*a(n-1) - 18*a(n-2) with a(0)=1, a(1)=5.

Original entry on oeis.org

1, 5, 32, 230, 1724, 13100, 99968, 763880, 5839376, 44643920, 341330432, 2609713760, 19953189824, 152557050560, 1166413088768, 8918103977600, 68185604178176, 521330170184960, 3985960826642432, 30475665203095040
Offset: 0

Views

Author

Al Hakanson (hawkuu(AT)gmail.com), Nov 03 2008

Keywords

Comments

The Mathematica program implements the formula provided by Deleham and Brockhaus. - Harvey P. Dale, Feb 17 2011

Programs

  • GAP
    a:=[1,5];; for n in [3..30] do a[n]:=10*a[n-1]-18*a[n-2]; od; a; # G. C. Greubel, Jan 08 2020
  • Magma
    Z:= PolynomialRing(Integers()); N:=NumberField(x^2-7); S:=[ ((5+r7)^n+(5-r7)^n)/2: n in [0..19] ]; [ Integers()!S[j]: j in [1..#S] ]; // Klaus Brockhaus, Nov 05 2008
    
  • Maple
    seq(coeff(series((1-5*x)/(1-10*x+18*x^2), x, n+1), x, n), n = 0..30); # G. C. Greubel, Jan 08 2020
  • Mathematica
    Transpose[NestList[{#[[2]],10#[[2]]-18#[[1]]}&,{1,5},20]][[1]]  (* Harvey P. Dale, Feb 17 2011 *)
    LinearRecurrence[{10,-18},{1,5},30] (* Harvey P. Dale, Aug 27 2013 *)
  • PARI
    my(x='x+O('x^30)); Vec((1-5*x)/(1-10*x+18*x^2)) \\ G. C. Greubel, Jan 08 2020
    
  • Sage
    def A146965_list(prec):
        P. = PowerSeriesRing(ZZ, prec)
        return P( (1-5*x)/(1-10*x+18*x^2) ).list()
    A146965_list(30) # G. C. Greubel, Jan 08 2020
    

Formula

a(n) = ((5 + sqrt(7))^n + (5 - sqrt(7))^n)/2.
G.f.: (1-5*x)/(1-10*x+18*x^2). - Philippe Deléham and Klaus Brockhaus, Nov 05 2008
a(n) = (Sum_{k=0..n} A098158(n,k)*5^(2*k)*7^(n-k))/5^n. - Philippe Deléham, Nov 06 2008
E.g.f.: exp(5*x)*cosh(sqrt(7)*x). - G. C. Greubel, Jan 08 2020

Extensions

Extended beyond a(7) by Klaus Brockhaus, Nov 05 2008
Name from Philippe Deléham and Klaus Brockhaus, Nov 05 2008

A146966 a(n) = ((6 + sqrt(7))^n + (6 - sqrt(7))^n) / 2.

Original entry on oeis.org

1, 6, 43, 342, 2857, 24366, 209539, 1807854, 15617617, 134983638, 1166892763, 10088187654, 87218361721, 754062898686, 6519422294323, 56365243469982, 487319675104417, 4213244040623526, 36426657909454219, 314935817735368374
Offset: 0

Views

Author

Al Hakanson (hawkuu(AT)gmail.com), Nov 03 2008

Keywords

Examples

			a(3) = ((6 + sqrt(7))^3 + (6 - sqrt(7))^3) / 2 = 342.
		

Programs

  • GAP
    a:=[1,6];; for n in [3..20] do a[n]:12*a[n-1]-29*a[n-2]; od; a; # G. C. Greubel, Jan 08 2020
  • Magma
    Z:= PolynomialRing(Integers()); N:=NumberField(x^2-7); S:=[ ((6+r7)^n+(6-r7)^n)/2: n in [0..19] ]; [ Integers()!S[j]: j in [1..#S] ]; // Klaus Brockhaus, Nov 05 2008
    
  • Magma
    I:=[1,6]; [n le 2 select I[n] else 12*Self(n-1)-29*Self(n-2): n in [1..30]]; // Vincenzo Librandi, Jan 31 2016
    
  • Maple
    f:= gfun:-rectoproc({a(n) = 12*a(n-1)-29*a(n-2), a(0)=1, a(1)=6},a(n),remember):
    map(f, [$0..100]); # Robert Israel, Feb 01 2016
  • Mathematica
    RecurrenceTable[{a[1]==1, a[2]==6, a[n]== 12 a[n-1] - 29 a[n-2]}, a, {n, 20}] (* Vincenzo Librandi, Jan 31 2016 *)
    LinearRecurrence[{12,-29},{1,6},20] (* Harvey P. Dale, Apr 17 2018 *)
  • PARI
    Vec((1-6*x)/(1-12*x+29*x^2) + O(x^30)); \\ Michel Marcus, Jan 31 2016
    
  • Sage
    def A146966_list(prec):
        P. = PowerSeriesRing(ZZ, prec)
        return P( (1-6*x)/(1-12*x+29*x^2) ).list()
    A146966_list(20) # G. C. Greubel, Jan 08 2020
    

Formula

a(n) = 12*a(n-1)-29*a(n-2), a(0)=1, a(1)=6. - Philippe Deléham, Nov 05 2008
G.f.: (1-6*x)/(1-12*x+29*x^2). - Klaus Brockhaus, Nov 05 2008
a(n) = (Sum_{k=0..n} A098158(n,k)*6^(2*k)*7^(n-k))/6^n. - Philippe Deléham, Nov 06 2008
E.g.f.: exp(6*x)*cosh(sqrt(7)*x). - G. C. Greubel, Jan 08 2020

Extensions

Extended beyond a(7) by Klaus Brockhaus, Nov 05 2008
Typo in name corrected by Sean Reeves, Dec 19 2015

A147689 a(n) = ((7 + sqrt(8))^n + (7 - sqrt(8))^n)/2.

Original entry on oeis.org

1, 7, 57, 511, 4817, 46487, 453321, 4440527, 43581217, 428075431, 4206226137, 41336073247, 406249753841, 3992717550647, 39241805801577, 385683861645551, 3790660025173057, 37256202024955207, 366169767317277561
Offset: 0

Views

Author

Al Hakanson (hawkuu(AT)gmail.com), Nov 10 2008

Keywords

Programs

  • Magma
    Z:= PolynomialRing(Integers()); N:=NumberField(x^2-8); S:=[ ((7+r8)^n+(7-r8)^n)/2: n in [0..18] ]; [ Integers()!S[j]: j in [1..#S] ]; // Klaus Brockhaus, Nov 13 2008
  • Mathematica
    LinearRecurrence[{14,-41},{1,7},20] (* Harvey P. Dale, Sep 11 2020 *)

Formula

From Philippe Deléham, Nov 13 2008: (Start)
a(n) = 14*a(n-1) - 41*a(n-2), a(0)=1, a(1)=7.
G.f.: (1-7x)/(1-14x+41x^2).
a(n) = (Sum_{k=0..n} A098158(n,k)*7^(2k)*8^(n-k))/7^n. (End)

Extensions

Extended beyond a(6) by Klaus Brockhaus, Nov 13 2008

A147961 a(n) = ((6+sqrt(3))^n + (6-sqrt(3))^n)/2.

Original entry on oeis.org

1, 6, 39, 270, 1953, 14526, 109863, 838998, 6442497, 49623030, 382873959, 2956927518, 22848289569, 176600866734, 1365216845031, 10554773538150, 81605126571777, 630953992102374, 4878478728359847, 37720263000939822, 291653357975402913, 2255071616673820830, 17436298586897553831
Offset: 0

Views

Author

Al Hakanson (hawkuu(AT)gmail.com), Nov 17 2008

Keywords

Examples

			a(3)=270
		

Crossrefs

Cf. A098158.

Programs

  • Magma
    Z:= PolynomialRing(Integers()); N:=NumberField(x^2-3); S:=[ ((6+r3)^n+(6-r3)^n)/2: n in [0..19] ]; [ Integers()!S[j]: j in [1..#S] ]; // Klaus Brockhaus, Nov 19 2008
  • Mathematica
    CoefficientList[Series[(1-6x)/(1-12x+33x^2),{x,0,30}],x] (* or *) LinearRecurrence[{12,-33},{1,6},30] (* Harvey P. Dale, Jul 30 2021 *)

Formula

From Philippe Deléham, Nov 19 2008: (Start)
a(n) = 12*a(n-1) - 33*a(n-2) for n > 1, with a(0)=1, a(1)=6.
G.f.: (1-6x)/(1-12x+33x^2).
a(n) = (Sum_{k=0..n} A098158(n,k)*6^(2k)*3^(n-k))/6^n. (End)
E.g.f.: exp(6*x)*cosh(sqrt(3)*x). - Stefano Spezia, Apr 23 2025

Extensions

Extended beyond a(6) by Klaus Brockhaus, Nov 19 2008
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