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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A189741 a(1)=4, a(2)=2, a(n) = 4*a(n-1) + 2*a(n-2).

Original entry on oeis.org

4, 2, 16, 68, 304, 1352, 6016, 26768, 119104, 529952, 2358016, 10491968, 46683904, 207719552, 924246016, 4112423168, 18298184704, 81417585152, 362266710016, 1611902010368, 7172141461504, 31912369866752, 141993762390016, 631799789293568, 2811186681954304
Offset: 1

Views

Author

Harvey P. Dale, Apr 26 2011

Keywords

Crossrefs

Programs

  • Mathematica
    LinearRecurrence[{4,2},{4,2},40]
  • Maxima
    a[1]:4$ a[2]:2$ a[n]:=4*a[n-1]+2*a[n-2]$ makelist(a[n], n, 1, 25);  /* Bruno Berselli, May 24 2011 */

Formula

G.f.: 2*x*(2-7*x)/(1-4*x-2*x^2). - Bruno Berselli, May 24 2011

A189734 a(1)=2, a(2)=5, a(n)=2*a(n-1) + 5*a(n-2).

Original entry on oeis.org

2, 5, 20, 65, 230, 785, 2720, 9365, 32330, 111485, 384620, 1326665, 4576430, 15786185, 54454520, 187839965, 647952530, 2235104885, 7709972420, 26595469265, 91740800630, 316458947585, 1091621898320, 3765538534565, 12989186560730, 44806065794285
Offset: 1

Views

Author

Harvey P. Dale, Apr 26 2011

Keywords

Crossrefs

Programs

  • Mathematica
    LinearRecurrence[{2,5},{2,5},40]
  • Maxima
    a[1]:2$ a[2]:5$ a[n]:=2*a[n-1]+5*a[n-2]$ makelist(a[n], n, 1, 26); /* Bruno Berselli, May 24 2011 */

Formula

G.f.: x*(2+x)/(1-2*x-5*x^2). - Bruno Berselli, May 24 2011

A189736 a(1)=3, a(2)=2, a(n)=3*a(n-1) + 2*a(n-2).

Original entry on oeis.org

3, 2, 12, 40, 144, 512, 1824, 6496, 23136, 82400, 293472, 1045216, 3722592, 13258208, 47219808, 168175840, 598967136, 2133253088, 7597693536, 27059586784, 96374147424, 343241615840, 1222473142368, 4353902658784, 15506654261088, 55227768100832
Offset: 1

Views

Author

Harvey P. Dale, Apr 26 2011

Keywords

Crossrefs

Programs

  • Mathematica
    LinearRecurrence[{3,2},{3,2},40]
  • Maxima
    a[1]:3$ a[2]:2$ a[n]:=3*a[n-1]+2*a[n-2]$ makelist(a[n], n, 1, 26); /* Bruno Berselli, May 24 2011 */

Formula

G.f.: x*(3-7*x)/(1-3*x-2*x^2). - Bruno Berselli, May 24 2011

A189742 a(1)=4, a(2)=3, a(n) = 4*a(n-1) + 3*a(n-2).

Original entry on oeis.org

4, 3, 24, 105, 492, 2283, 10608, 49281, 228948, 1063635, 4941384, 22956441, 106649916, 495468987, 2301825696, 10693709745, 49680316068, 230802393507, 1072250522232, 4981409269449, 23142388644492, 107513782386315, 499482295478736, 2320470529073889
Offset: 1

Views

Author

Harvey P. Dale, Apr 26 2011

Keywords

Crossrefs

Programs

  • Mathematica
    LinearRecurrence[{4,3},{4,3},40]
  • Maxima
    a[1]:4$ a[2]:3$ a[n]:=4*a[n-1]+3*a[n-2]$ makelist(a[n], n, 1, 24); /* Bruno Berselli, May 24 2011 */

Formula

G.f.: x*(4-13*x)/(1-4*x-3*x^2). - Bruno Berselli, May 24 2011

A189743 a(1)=4, a(2)=4, a(n) = 4*a(n-1) + 4*a(n-2).

Original entry on oeis.org

4, 4, 32, 144, 704, 3392, 16384, 79104, 381952, 1844224, 8904704, 42995712, 207601664, 1002389504, 4839964672, 23369416704, 112837525504, 544827768832, 2630661177344, 12701955784704, 61330467848192, 296129694531584, 1429840649519104, 6903881376202752
Offset: 1

Views

Author

Harvey P. Dale, Apr 26 2011

Keywords

Crossrefs

Programs

  • Mathematica
    LinearRecurrence[{4,4},{4,4},40]
  • Maxima
    a[1]:4$ a[2]:4$ a[n]:=4*a[n-1]+4*a[n-2]$ makelist(a[n], n, 1, 24); /* Bruno Berselli, May 24 2011 */

Formula

G.f.: 4*x*(1-3*x)/(1-4*x-4*x^2). - Bruno Berselli, May 24 2011

A189744 a(1)=4, a(2)=5, a(n) = 4*a(n-1) + 5*a(n-2).

Original entry on oeis.org

4, 5, 40, 185, 940, 4685, 23440, 117185, 585940, 2929685, 14648440, 73242185, 366210940, 1831054685, 9155273440, 45776367185, 228881835940, 1144409179685, 5722045898440, 28610229492185, 143051147460940, 715255737304685, 3576278686523440, 17881393432617185
Offset: 1

Views

Author

Harvey P. Dale, Apr 26 2011

Keywords

Crossrefs

Programs

  • Magma
    [5/2*(-1)^(n-1)+3/2*5^(n-1): n in [1..30]]; // Vincenzo Librandi, Jul 15 2011
    
  • Mathematica
    LinearRecurrence[{4,5},{4,5},40]
  • Maxima
    a[1]:4$ a[2]:5$ a[n]:=4*a[n-1]+5*a[n-2]$ makelist(a[n], n, 1, 24); /* Bruno Berselli, May 24 2011 */
    
  • PARI
    a(n)=5/2*(-1)^(n-1)+3/2*5^(n-1) \\ Charles R Greathouse IV, Jul 02 2013

Formula

G.f.: x*(4-11*x)/(1 - 4*x - 5*x^2). - Bruno Berselli, May 24 2011

A189745 a(n) = 5*a(n-1) + a(n-2); with a(1)=5, a(2)=1.

Original entry on oeis.org

5, 1, 10, 51, 265, 1376, 7145, 37101, 192650, 1000351, 5194405, 26972376, 140056285, 727253801, 3776325290, 19608880251, 101820726545, 528712512976, 2745383291425, 14255628970101, 74023528141930, 384373269679751, 1995889876540685, 10363822652383176
Offset: 1

Views

Author

Harvey P. Dale, Apr 26 2011

Keywords

Crossrefs

Programs

  • Mathematica
    LinearRecurrence[{5,1},{5,1},40]
  • Maxima
    a[1]:5$ a[2]:1$ a[n]:=5*a[n-1]+a[n-2]$ makelist(a[n], n, 1, 24); /*
     Bruno Berselli, May 24 2011 */

Formula

G.f.: x*(5-24*x)/(1-5*x-x^2). - Bruno Berselli, May 24 2011

A189749 a(1)=5, a(2)=5, a(n)=5*a(n-1) + 5*a(n-2).

Original entry on oeis.org

5, 5, 50, 275, 1625, 9500, 55625, 325625, 1906250, 11159375, 65328125, 382437500, 2238828125, 13106328125, 76725781250, 449160546875, 2629431640625, 15392960937500, 90111962890625, 527524619140625, 3088182910156250, 18078537646484375, 105833602783203125
Offset: 1

Views

Author

Harvey P. Dale, Apr 26 2011

Keywords

Crossrefs

Programs

  • Mathematica
    LinearRecurrence[{5,5},{5,5},40]
  • Maxima
    a[1]:5$ a[2]:5$ a[n]:=5*a[n-1]+5*a[n-2]$ makelist(a[n], n, 1, 23); /* Bruno Berselli, May 24 2011 */

Formula

G.f.: 5*x*(1-4*x)/(1-5*x-5*x^2). - Bruno Berselli, May 24 2011
a(n) = 5*A188168(n). - R. J. Mathar, Feb 13 2020

A106435 a(n) = 3*a(n-1) + 3*a(n-2), a(0)=0, a(1)=3.

Original entry on oeis.org

0, 3, 9, 36, 135, 513, 1944, 7371, 27945, 105948, 401679, 1522881, 5773680, 21889683, 82990089, 314639316, 1192888215, 4522582593, 17146412424, 65006985051, 246460192425, 934401532428, 3542585174559, 13430960120961
Offset: 0

Views

Author

Roger L. Bagula, May 29 2005

Keywords

Comments

The first entry of the vector v[n] = M*v[n-1], where M is the 2 x 2 matrix [[0,3],[1,3]] and v[1] is the column vector [0,1]. The characteristic polynomial of the matrix M is x^2-3x-3.

Crossrefs

Programs

  • Haskell
    a106435 n = a106435_list !! n
    a106435_list = 0 : 3 : map (* 3) (zipWith (+) a106435_list (tail
    a106435_list))
    -- Reinhard Zumkeller, Oct 15 2011
    
  • Magma
    a:=[0,3]; [n le 2 select a[n] else    3*Self(n-1) + 3*Self(n-2) : n in [1..24]]; // Marius A. Burtea, Jan 21 2020
    
  • Magma
    R:=PowerSeriesRing(Rationals(), 25); Coefficients(R!(3*x/(1-3*x-3*x^2))); // Marius A. Burtea, Jan 21 2020
    
  • Maple
    seq(coeff(series(3*x/(1-3*x-3*x^2), x, n+1), x, n), n = 0..30); # G. C. Greubel, Mar 12 2020
  • Mathematica
    LinearRecurrence[{3,3}, {0,3}, 30] (* G. C. Greubel, Mar 12 2020 *)
  • PARI
    a(n)=([0,3;1,3]^n)[1,2]
    
  • Sage
    [3^((n+1)/2)*i^(1-n)*chebyshev_U(n-1, i*sqrt(3)/2) for n in (0..30)] # G. C. Greubel, Mar 12 2020

Formula

G.f.: 3*x/(1-3*x-3*x^2). - Philippe Deléham, Nov 19 2008
From G. C. Greubel, Mar 12 2020: (Start)
a(n) = 3^((n+1)/2) * Fibonacci(n, sqrt(3)), where F(n, x) is the Fibonacci polynomial.
a(n) = 3^((n+1)/2)*i^(1-n)*ChebyshevU(n-1, i*sqrt(3)/2). (End)

Extensions

Edited by N. J. A. Sloane, May 20 2006 and May 29 2006
Offset corrected by Reinhard Zumkeller, Oct 15 2011

A189737 a(1)=3, a(2)=3, a(n)=3*a(n-1) + 3*a(n-2).

Original entry on oeis.org

3, 3, 18, 63, 243, 918, 3483, 13203, 50058, 189783, 719523, 2727918, 10342323, 39210723, 148659138, 563609583, 2136806163, 8101247238, 30714160203, 116446222323, 441481147578, 1673782109703, 6345789771843, 24058715644638, 91213516249443, 345816695682243
Offset: 1

Views

Author

Harvey P. Dale, Apr 26 2011

Keywords

Crossrefs

Programs

  • Mathematica
    LinearRecurrence[{3,3},{3,3},40]
  • Maxima
    a[1]:3$ a[2]:3$ a[n]:=3*a[n-1]+3*a[n-2]$ makelist(a[n], n, 1, 26); /* Bruno Berselli, May 24 2011 */

Formula

G.f.: 3*x*(1-2*x)/(1-3*x-3*x^2). - Bruno Berselli, May 24 2011
Previous Showing 11-20 of 37 results. Next