I think
$f(x) = \sum_{n=1}^{\infty}(-1)^n \frac{x^{2n-1}}{(2n)! \ln 2n}$ is totally monotone.
Bernstein's theorem and his integral transform convinced me.
Am I correct ?
Probably related or useful is a function like
$f(x,k) = \sum_{n=1}^{\infty}(-1)^n \frac{x^{2n-1}}{(2n)! \ln (2n+k)}$
which follows or almost follows from differentiating.
This is a follow-up of the question
A curious limit for $-\frac{\pi}{2}$
about the same function.
so basically for $ x> 0$ the derivatives alternate in sign.
– mick Jan 21 '23 at 23:25