## Determinant representations of Appell polynomial sequences.(English)Zbl 1166.15003

The Appell polynomial sequence $$(a_n)$$, $$n=0,1,2,\dots$$, associated with a function $$g$$ is defined recursively by differential equations $$a_n'(x)=na_{n-1}(x)$$ with initial conditions $$a_n(0)=h^{(n)}(0)$$ where $$h=1/g$$.
It is proved that
$a_n(x)=(-1)^n\frac{n!}{g_0^{n+1}} \begin{vmatrix} 1&g_0&0&0&\dots&0 \\ \frac{x}{1!}&g_1&g_0&0&\dots&0 \\ \frac{x^2}{2!}&g_2&g_1&g_0&\dots&0 \\ \vdots&\vdots&\vdots&\vdots&&\vdots \\ \frac{x^{n-1}}{(n-1)!}&g_{n-1}&g_{n-2}&g_{n-3}&\dots&g_0 \\ \frac{x^n}{n!}&g_n&g_{n-1}&g_{n-2}&\dots&g_1 \end{vmatrix}$
where $$g_k=\frac{g^{(k)}(0)}{k!}$$, $$k=0,1,\dots,n$$. As special cases, determinantal representations for Bernoulli and Euler polynomials are obtained.
The proof applies the Leibniz matrix associated with a function $$f$$ and a nonnegative integer $$n$$, defined by
${\mathcal L}_n(f(x))= \begin{pmatrix} f(x)&0&0&0&\dots&0 \\ \frac{f'(x)}{1!}&f(x)&0&0&\dots&0 \\ \frac{f''(x)}{2!}&\frac{f'(x)}{1!}&f(x)&0&\dots&0 \\ \vdots&\vdots&\vdots&\vdots&&\vdots \\ \frac{f^{(n)}(x)}{n!}&\frac{f^{(n-1)}(x)}{(n-1)!}& \frac{f^{(n-2)}(x)}{(n-2)!}&\dots&\dots&f(x) \end{pmatrix},$
see D. Kalman and A. Ungar [Am. Math. Mon. 94, 21–35 (1987; Zbl 0622.05002)].

### MSC:

 15A15 Determinants, permanents, traces, other special matrix functions 05A40 Umbral calculus 11B68 Bernoulli and Euler numbers and polynomials 33C65 Appell, Horn and Lauricella functions

Zbl 0622.05002
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