For my high school math project I studied polynomial interpolation: given a set of points $(x_0,y_0),...,(x_n,y_n)$, find the polynomial of degree $n$ that passes through all points. The solutions by Newton and Lagrange are well known, but I wanted to know the coefficients of the polynomial in standard form (powers of $x$). Using elementary algebra I solved the cases up to $n=3$ and generalized this to
$$ V(x) = \sum^n_{i=0}(-1)^{n-i}\sum^n_{j=0}y_j\frac{e_{n-i}(x_0,...,x_{j-1},x_{j+1},...,x_n)}{\prod^n_{k=0,k\neq j}(x_j-x_k)}x^i $$
where $e_k(S)$ is the elementary symmetric polynomial (ESP). I also proved this. Later, I found out that V(x) is equivalent to the solution using Vandermonde's matrix, see the answer to exercise 40 in Knuth's The Art of Computer Programming, vol. 1, section 1.2.3. Sums and products. The only difference is that Vandermonde doesn't use the ESP. Lagrange's solution is expressed in elementary algebra, Newton's solution uses the divided differences (DD) $[y_0,...,y_n]$, and Vandermonde's solution can be expressed using ESP. So I wondered whether there is a solution using both DD and ESP. And there is. My solution is
$$H(x) = \sum^n_{i=0}\sum^n_{j=i}[y_0,...,y_j](-1)^{j-i}e_{j-i}(x_0,...,x_{j-1})x^i$$
It can be derived from Newton's solution and from Vandermonde's solution. After finding the solution tried to find it in (online) literature but I couldn't. I asked my math teacher and a university math professor and both did not know where it can be found. (Question) Who knows where to find the solution $H(x)$ in math literature?