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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A015544 Lucas sequence U(5,-8): a(n+1) = 5*a(n) + 8*a(n-1), a(0)=0, a(1)=1.

Original entry on oeis.org

0, 1, 5, 33, 205, 1289, 8085, 50737, 318365, 1997721, 12535525, 78659393, 493581165, 3097180969, 19434554165, 121950218577, 765227526205, 4801739379641, 30130517107845, 189066500576353, 1186376639744525, 7444415203333449, 46713089134623445
Offset: 0

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Author

Keywords

Crossrefs

Programs

  • Magma
    [n le 2 select n-1 else 5*Self(n-1) + 8*Self(n-2): n in [1..30]]; // Vincenzo Librandi, Nov 13 2012
    
  • Mathematica
    a[n_]:=(MatrixPower[{{1,2},{1,-6}},n].{{1},{1}})[[2,1]]; Table[Abs[a[n]],{n,-1,40}] (* Vladimir Joseph Stephan Orlovsky, Feb 19 2010 *)
    LinearRecurrence[{5, 8}, {0, 1}, 30] (* Vincenzo Librandi, Nov 13 2012 *)
  • PARI
    A015544(n)=imag((2+quadgen(57))^n) \\ M. F. Hasler, Mar 06 2009
    
  • PARI
    x='x+O('x^30); concat([0], Vec(x/(1 - 5*x - 8*x^2))) \\ G. C. Greubel, Jan 01 2018
  • Sage
    [lucas_number1(n,5,-8) for n in range(0, 21)] # Zerinvary Lajos, Apr 24 2009
    

Formula

a(n) = 5*a(n-1) + 8*a(n-2).
G.f.: x/(1 - 5*x - 8*x^2). - M. F. Hasler, Mar 06 2009

Extensions

More precise definition by M. F. Hasler, Mar 06 2009

A106569 a(n) = 5*a(n-1) + 3*a(n-2), where a(0) = 0, a(1) = 3.

Original entry on oeis.org

0, 3, 15, 84, 465, 2577, 14280, 79131, 438495, 2429868, 13464825, 74613729, 413463120, 2291156787, 12696173295, 70354336836, 389860204065, 2160364030833, 11971400766360, 66338095924299, 367604681920575
Offset: 0

Views

Author

Roger L. Bagula, May 30 2005

Keywords

Crossrefs

Cf. A015536.

Programs

  • Magma
    [n le 2 select 3*(n-1) else 5*Self(n-1) + 3*Self(n-2): n in [1..41]]; // G. C. Greubel, Sep 07 2021
    
  • Maple
    a[0]:=0: a[1]:=3: for n from 2 to 23 do a[n]:= 5*a[n-1]+3*a[n-2] od: seq(a[n], n=0..23);
  • Mathematica
    LinearRecurrence[{5,3}, {0,3}, 40] (* G. C. Greubel, Sep 07 2021 *)
  • Sage
    [3*lucas_number1(n,5,-3) for n in (0..40)] # G. C. Greubel, Sep 07 2021

Formula

a(n) = 5*a(n-1) + 3*a(n-2), a(0) = 0, a(1) = 3.
a(n) = 3*A015536(n).
G.f.: 3*x/(1 - 5*x - 3*x^2). - G. C. Greubel, Sep 07 2021

Extensions

Edited by N. J. A. Sloane, Apr 30 2006
New (corrected) name by G. C. Greubel, Sep 07 2021

A271451 Triangle read by rows of coefficients of polynomials Q_n(x) = 2^(-n)*((x + sqrt(x*(x + 6) - 3) + 1)^n - (x - sqrt(x*(x + 6) - 3) + 1)^n)/sqrt(x*(x + 6) - 3).

Original entry on oeis.org

1, 1, 1, 0, 3, 1, -1, 3, 5, 1, -1, -1, 10, 7, 1, 0, -6, 7, 21, 9, 1, 1, -6, -10, 31, 36, 11, 1, 1, 1, -29, 7, 79, 55, 13, 1, 0, 9, -24, -63, 81, 159, 78, 15, 1, -1, 9, 15, -123, -54, 264, 279, 105, 17, 1, -1, -1, 57, -69, -321, 132, 624, 447, 136, 19, 1, 0, -12, 50, 126, -459, -507, 741, 1245, 671, 171, 21, 1, 1, -12, -20, 302, -81, -1419, -258, 2163, 2227, 959, 210, 23, 1
Offset: 1

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Author

Ilya Gutkovskiy, Apr 08 2016

Keywords

Comments

The polynomials Q_n(x) have generating function G(x,t) = t/(1 - (x + 1)*t - (x - 1)*t^2) = t + (x + 1)*t^2 + x*(x + 3)*t^3 + (x^3 + 5*x^2 + 3*x - 1)*t^4 + ...
Q_n(x) can be defined by the recurrence relation Q_n(x) = (x + 1)*Q_(n-1)(x) + (x - 1)*Q_(n-2)(x), Q_0(x)=0, Q_1(x)=1.
Discriminants of Q_n(x) gives the sequence: 0, 1, 1, 9, 320, 35600, 10948608, 8664190976, 16836271800320, 77757312009240576, 833309554769920000000, 20346889104219547132493824,...
Q_n(0) = A128834(n).
Q_n(1) = A000079(n-1), n>0.
Q_n(2) = A006190(n).
Q_n(3) = A090017(n).
Q_n(4) = A015536(n).
Q_n(5) = A135032(n).
Q_n(6) = A015562(n).
Q_n(7) = A190560(n).
Q_n(8) = A015583(n).
Q_n(9) = A190957(n).
Q_n(10) = A015603(n).

Examples

			Triangle begins:
   1;
   1,  1;
   0,  3,  1;
  -1,  3,  5,  1;
  -1, -1, 10,  7,  1;
...
The first few polynomials are:
Q_0(x) = 0;
Q_1(x) = 1;
Q_2(x) = x + 1;
Q_3(x) = x^2 + 3*x;
Q_4(x) = x^3 + 5*x^2 + 3*x - 1;
Q_5(x) = x^4 + 7*x^3 + 10*x^2 - x - 1,
...
		

Crossrefs

Cf. A049310.

Programs

  • Mathematica
    Flatten[Table[CoefficientList[((x + Sqrt[x (x + 6) - 3] + 1)^n - (x - Sqrt[x (x + 6) - 3] + 1)^n)/2^n/Sqrt[x (x + 6) - 3], x], {n, 0, 13}]]

A111365 a(n) = 5*a(n-1) + 3*a(n-2) where a(0) = a(1) = 1.

Original entry on oeis.org

1, 1, 8, 43, 239, 1324, 7337, 40657, 225296, 1248451, 6918143, 38336068, 212434769, 1177182049, 6523214552, 36147618907, 200307738191, 1109981547676, 6150830952953, 34084099407793, 188872989897824, 1046617247712499
Offset: 0

Views

Author

Parthasarathy Nambi, Nov 07 2005

Keywords

Examples

			a(2) = 5*a(1) + 3*a(0) = 5*1 + 3*1 = 8 which is the third term in the sequence.
		

References

  • Thomas Koshy, "Fibonacci and Lucas Numbers with Applications", Wiley, 2001

Crossrefs

Programs

  • Mathematica
    Transpose[NestList[Flatten[{Rest[#],ListCorrelate[{3,5},#]}]&, {1,1},40]][[1]]  (* Harvey P. Dale, Mar 23 2011 *)

Formula

a(n)=A015536(n+1)-4*A015536(n). G.f.: (1-4x)/(1-5x-3x^2). [From R. J. Mathar, Jul 08 2009]

Extensions

More terms from Robert G. Wilson v, Nov 10 2005
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