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Floor of the imaginary parts of the zeros of the complex Lucas function on the left half-plane.
3

%I #16 Mar 09 2024 08:17:29

%S 0,0,1,1,2,3,3,4,4,5,5,6,7,7,8,8,9,9,10,10,11,12,12,13,13,14,14,15,15,

%T 16,17,17,18,18,19,19,20,21,21,22,22,23,23,24,24,25,26,26,27,27,28,28,

%U 29,29,30,31,31,32,32,33,33,34,35,35,36

%N Floor of the imaginary parts of the zeros of the complex Lucas function on the left half-plane.

%C For the complex Lucas function L(z) and its zeros see the comments in A214671 and the Koshy reference.

%D Thomas Koshy, "Fibonacci and Lucas Numbers with Applications", John Wiley and Sons, 2001.

%H G. C. Greubel, <a href="/A214672/b214672.txt">Table of n, a(n) for n = 0..10000</a>

%F a(n) = floor((2*n+1)*b/2), n >= 0, with b/2 = -y_0(0) = 2*Pi*log(phi) / (Pi^2 + (2*log(phi))^2), with phi = (1+sqrt(5))/2. Note that b/2 is approximately 0.2800649542... . The constant b appears in the corresponding Fibonacci case A214656.

%t Table[Floor[(2*n+1)*(2*Pi*Log[GoldenRatio])/(Pi^2 + (2*Log[GoldenRatio])^2)], {n, 0, 100}] (* _G. C. Greubel_, Mar 09 2024 *)

%o (Magma) R:= RealField(100); [Floor((2*n+1)*(2*Pi(R)*Log((1 + Sqrt(5))/2))/(Pi(R)^2 + (2*Log((1+Sqrt(5))/2))^2)) : n in [0..100]]; // _G. C. Greubel_, Mar 09 2024

%o (SageMath) [floor(2*(2*n+1)*pi*log(golden_ratio)/(pi^2 +4*(log(golden_ratio))^2)) for n in range(101)] # _G. C. Greubel_, Mar 09 2024

%Y Cf. A214656 (Fibonacci case), A214671 (floor of real parts), A214673 (moduli).

%K nonn

%O 0,5

%A _Wolfdieter Lang_, Jul 25 2012