Imaginary zeros of f(z)= z^(1/z) (real valued solutions f(z)>e^(1/e))
#4
Nice graph!

I think Scott Draves once said that fractals are only half-way between math and art, the other half is coloring algorithms Smile

Anyways, I wanted to give some pointers to info about the Lambert W-function. Mostly anything published by Corless/Jeffery et.al. or Galidakis is a great place to start. I also have done research on it, and one of the series expansions I found for it could only be found on OEIS, but I'm assuming it has to be published somewhere, so I'm including it below.

I'm not sure if series expansions are really what you need, it sounds like you need Maple or Mathematica, but if it helps, here are the two series expansions I know for the solution to \( b = h^{1/h} \):

\(
h = {}^{\infty}{b} = \sum^{\infty}_{k=0} \frac{\log(b)^k}{k!} (k+1)^{(k-1)}
\)

found in (A000272) and using the Taylor-Puiseux conversion detailed in Abel Functional Equation, the other one is relatively easy to derive:

\(
h = {}^{\infty}{b} = \sum^{\infty}_{k=0} \frac{(b - 1)^k}{k!} \sum^k_{j=0} \left[{k \atop j}\right] (j+1)^{(j-1)}
\)

found in (A033917).

Andrew Robbins
Reply


Messages In This Thread
RE: Tetration below 1 - by Gottfried - 09/09/2007, 07:04 AM
RE: The Complex Lambert-W - by Gottfried - 09/09/2007, 04:54 PM
RE: The Complex Lambert-W - by andydude - 09/10/2007, 06:58 AM

Possibly Related Threads…
Thread Author Replies Views Last Post
  extending normal tetration to real numbers using product tetration Alex Zuma 2025 0 1,355 12/12/2025, 07:49 PM
Last Post: Alex Zuma 2025
  my proposed extension of the fast growing hierarchy to real numbers Alex Zuma 2025 0 1,660 09/28/2025, 07:15 PM
Last Post: Alex Zuma 2025
  Behaviour of tetration into the real negatives Shanghai46 1 6,843 03/24/2025, 12:34 AM
Last Post: MphLee
  X-th iteration where x is a real number Natsugou 1 6,088 10/27/2024, 11:23 PM
Last Post: MphLee
  Real and complex tetration Daniel 13 19,154 04/04/2023, 10:25 AM
Last Post: JmsNxn
  Range of complex tetration as real Daniel 2 5,530 10/22/2022, 08:08 PM
Last Post: Shanghai46
  From complex to real tetration Daniel 3 6,979 10/21/2022, 07:55 PM
Last Post: Daniel
  Cost of real tetration Daniel 1 4,390 09/30/2022, 04:41 PM
Last Post: bo198214
  Real Multivalued/Parametrized Iteration Groups bo198214 11 16,182 09/10/2022, 11:56 AM
Last Post: tommy1729
  Constructive real tetration Daniel 1 4,262 09/01/2022, 05:41 AM
Last Post: JmsNxn



Users browsing this thread: 3 Guest(s)