Narumi polynomials

In mathematics, Narumi polynomials are polynomials introduced by Narumi (1929)^[1] given by the generating function

${\displaystyle \sum _{n=0}^{\infty }{\frac {s_{n}(x)}{n!}}t^{n}=\left({\frac {t}{\log(1+t)}}\right)^{a}(1+t)^{x}.}$

They form the Sheffer sequence for^[2][3]

${\displaystyle g(t)={\Big (}{\frac {e^{t}-1}{t}}{\Big )}^{-a},\quad f(t)=e^{t}-1.}$