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.

A214315 Floor of the real part of the zeros of the complex Fibonacci function on the right half-plane.

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%I A214315 #18 Mar 09 2024 08:14:25
%S A214315 0,1,3,5,7,9,10,12,14,16,18,20,21,23,25,27,29,31,32,34,36,38,40,42,43,
%T A214315 45,47,49,51,53,54,56,58,60,62,63,65,67,69,71,73,74,76,78,80,82,84,85,
%U A214315 87,89,91,93,95,96,98,100,102,104,106,107,109,111,113,115,117,118
%N A214315 Floor of the real part of the zeros of the complex Fibonacci function on the right half-plane.
%C A214315 For the complex Fibonacci function and its complex zeros see the Koshy reference, pp. 523-524. See also the formula for F(z) given in the formula section of A052952. The real parts of the zeros of F are x_0(k) = alpha*k, with alpha = 2*(Pi^2)/(Pi^2 + (2*log(phi))^2), where phi = (1+sqrt(5))/2, and integer k. The corresponding imaginary parts are y_0(k) = - 4*Pi*log(phi)*k/(Pi^2 + (2*log(phi))^2). alpha is approximately 1.828404783. The zeros lie in the lower right and the upper left half-planes, and there is a zero at the origin.
%C A214315 a(n) = floor(alpha*n), n>=0, is a Beatty sequence with the complementary sequence b(n) = floor(beta*n), with beta = alpha/(alpha-1), approximately 2.207139336.
%C A214315 For the floor of the negative imaginary part see A214656.
%D A214315 Thomas Koshy, "Fibonacci and Lucas Numbers with Applications", John Wiley and Sons, 2001.
%H A214315 G. C. Greubel, <a href="/A214315/b214315.txt">Table of n, a(n) for n = 0..10000</a>
%F A214315 a(n) = floor(alpha*n), n>=0, with alpha = x_0(1) given in the comment section.
%e A214315 The complementary Beatty sequences start with:
%e A214315 n:    1   2 3  4  5  6   7   8   9  10  11  12  13  14  15  16
%e A214315 a(n): 0   1 3  5  7  9  10  12  14  16  18  20  21  23  25  27
%e A214315 b(n): (0) 2 4  6  8 11  13  15  17  19  22  24  26  28  30  33
%t A214315 a[n_]:= Floor[2*n*Pi^2/(Pi^2 + 4*Log[GoldenRatio]^2)]; Table[a[n], {n, 0, 65}] (* _Jean-François Alcover_, Jul 03 2013 *)
%o A214315 (Magma) R:= RealField(100); [Floor(2*n*Pi(R)^2/(Pi(R)^2 + (2*Log((1+Sqrt(5))/2))^2)) : n in [0..100]]; // _G. C. Greubel_, Mar 09 2024
%o A214315 (SageMath) [floor(2*n*pi^2/(pi^2 +4*(log(golden_ratio))^2)) for n in range(101)] # _G. C. Greubel_, Mar 09 2024
%Y A214315 Cf. A052952 (Fibonacci related formula), A214656.
%K A214315 nonn
%O A214315 0,3
%A A214315 _Wolfdieter Lang_, Jul 24 2012