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A214315
Floor of the real part of the zeros of the complex Fibonacci function on the right half-plane.
4
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, 45, 47, 49, 51, 53, 54, 56, 58, 60, 62, 63, 65, 67, 69, 71, 73, 74, 76, 78, 80, 82, 84, 85, 87, 89, 91, 93, 95, 96, 98, 100, 102, 104, 106, 107, 109, 111, 113, 115, 117, 118
OFFSET
0,3
COMMENTS
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.
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.
For the floor of the negative imaginary part see A214656.
REFERENCES
Thomas Koshy, "Fibonacci and Lucas Numbers with Applications", John Wiley and Sons, 2001.
LINKS
FORMULA
a(n) = floor(alpha*n), n>=0, with alpha = x_0(1) given in the comment section.
EXAMPLE
The complementary Beatty sequences start with:
n: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
a(n): 0 1 3 5 7 9 10 12 14 16 18 20 21 23 25 27
b(n): (0) 2 4 6 8 11 13 15 17 19 22 24 26 28 30 33
MATHEMATICA
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 *)
PROG
(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
(SageMath) [floor(2*n*pi^2/(pi^2 +4*(log(golden_ratio))^2)) for n in range(101)] # G. C. Greubel, Mar 09 2024
CROSSREFS
Cf. A052952 (Fibonacci related formula), A214656.
Sequence in context: A108598 A184808 A329837 * A249098 A287774 A308412
KEYWORD
nonn
AUTHOR
Wolfdieter Lang, Jul 24 2012
STATUS
approved