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.

Showing 1-2 of 2 results.

A294116 Fibonacci sequence beginning 2, 21.

Original entry on oeis.org

2, 21, 23, 44, 67, 111, 178, 289, 467, 756, 1223, 1979, 3202, 5181, 8383, 13564, 21947, 35511, 57458, 92969, 150427, 243396, 393823, 637219, 1031042, 1668261, 2699303, 4367564, 7066867, 11434431, 18501298, 29935729, 48437027, 78372756, 126809783, 205182539, 331992322, 537174861
Offset: 0

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Author

Bruno Berselli, Oct 23 2017

Keywords

References

  • Steven Vajda, Fibonacci and Lucas Numbers, and the Golden Section: Theory and Applications, Dover Publications (2008), page 24 (formula 8).

Crossrefs

Subsequence of A047201, A047592, A113763.
Sequences of the type g(2,k;n): A118658 (k=0), A000032 (k=1), 2*A000045 (k=2,4), A020695 (k=3), A001060 (k=5), A022112 (k=6), A022113 (k=7), A294157 (k=8), A022114 (k=9), A022367 (k=10), A022115 (k=11), A022368 (k=12), A022116 (k=13), A022369 (k=14), A022117 (k=15), A022370 (k=16), A022118 (k=17), A022371 (k=18), A022119 (k=19), A022372 (k=20), this sequence (k=21), A022373 (k=22); A022374 (k=24); A022375 (k=26); A022376 (k=28), A190994 (k=29), A022377 (k=30); A022378 (k=32).

Programs

  • Magma
    a0:=2; a1:=21; [GeneralizedFibonacciNumber(a0, a1, n): n in [0..40]];
    
  • Mathematica
    LinearRecurrence[{1, 1}, {2, 21}, 40]
  • PARI
    Vec((2 + 19*x)/(1 - x - x^2) + O(x^40)) \\ Colin Barker, Oct 25 2017
    
  • Sage
    a = BinaryRecurrenceSequence(1, 1, 2, 21)
    print([a(n) for n in range(38)]) # Peter Luschny, Oct 25 2017

Formula

G.f.: (2 + 19*x)/(1 - x - x^2).
a(n) = a(n-1) + a(n-2).
Let g(r,s;n) be the n-th generalized Fibonacci number with initial values r, s. We have:
a(n) = Lucas(n) + g(0,20;n), see A022354;
a(n) = Fibonacci(n) + g(2,20;n), see A022372;
a(n) = 2*g(1,21;n) - g(0,21;n);
a(n) = g(1,k;n) + g(1,21-k;n) for all k in Z.
a(h+k) = a(h)*Fibonacci(k-1) + a(h+1)*Fibonacci(k) for all h, k in Z (see S. Vajda in References section). For h=0 and k=n:
a(n) = 2*Fibonacci(n-1) + 21*Fibonacci(n).
Sum_{j=0..n} a(j) = a(n+2) - 21.
a(n) = (2^(-n)*((1-sqrt(5))^n*(-20+sqrt(5)) + (1+sqrt(5))^n*(20+sqrt(5)))) / sqrt(5). - Colin Barker, Oct 25 2017

A022387 Fibonacci sequence beginning 4, 30.

Original entry on oeis.org

4, 30, 34, 64, 98, 162, 260, 422, 682, 1104, 1786, 2890, 4676, 7566, 12242, 19808, 32050, 51858, 83908, 135766, 219674, 355440, 575114, 930554, 1505668, 2436222, 3941890, 6378112, 10320002, 16698114, 27018116, 43716230, 70734346, 114450576, 185184922, 299635498, 484820420
Offset: 0

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Author

Keywords

Crossrefs

Equals 2 * A022117.

Programs

  • GAP
    List([0..40],n->4*Fibonacci(n+2)+22*Fibonacci(n)); # Muniru A Asiru, Mar 03 2018
  • Magma
    I:=[4,30]; [n le 2 select I[n] else Self(n-1) + Self(n-2): n in [1..40]]; // Vincenzo Librandi, Oct 17 2012
    
  • Magma
    [4*Fibonacci(n+2) + 22*Fibonacci(n): n in [0..40]]; // G. C. Greubel, Mar 01 2018
    
  • Maple
    with(combinat,fibonacci):  seq(4*fibonacci(n+2)+22*fibonacci(n),n=0..35); # Muniru A Asiru, Mar 03 2018
  • Mathematica
    LinearRecurrence[{1, 1}, {4, 30}, 30] (* Harvey P. Dale, Oct 16 2012 *)
    CoefficientList[Series[(4 + 26 * x)/(1 - x - x^2), {x, 0, 30}], x] (* Vincenzo Librandi, Oct 17 2012 *)
    Table[4 * Fibonacci[n + 2] + 22 * Fibonacci[n], {n, 0, 50}] (* G. C. Greubel, Mar 02 2018 *)
  • PARI
    for(n=0, 40, print1(4*fibonacci(n+2) + 22*fibonacci(n), ", ")) \\ G. C. Greubel, Mar 01 2018
    

Formula

G.f.: (4+26*x)/(1-x-x^2). - Philippe Deléham, Nov 19 2008
a(n) = 4*Fibonacci(n+2) + 22*fibonacci(n) = 4*Fibonacci(n-1) + 30*Fibonacci(n). - G. C. Greubel, Mar 02 2018
Showing 1-2 of 2 results.