Mike, N3LI wrote:
"I thought that the inductance tends donward as the diameter of the wire
increases. I can understand your calculation after the wavelength part,
but don`t quite get the increased inductance part."

Good observation.

Wire inductance decreases with the circumference increase as this
effectively places more parallel inductors in place along the surface of
the wire.

Wire capacitance increases proportionally with the square of the
circunference of the wire as it is proportional to the wire`s surface
area.

The fatter wire grows capacitance faster than it changes inductance.

Reactance along a wire antenna element varies quickly near resonant and
antiresonant points so is not uniformly distributed. This complicates
calculations and requires average values for some. Bailey says of surge
impedance: "Nevertheless, this variation in theoretical surge impedance
shall not deter us from setting uup practical "average" values of surge
impedance.
Best regards, Richard Harrison, KB5WZI