:16024966
$$
\begin{align}
\sum_{k,n=1}^\infty\frac1{n^2k(n+k)^2}
&=\frac12\sum_{k,n=1}^\infty\left(\frac1{n^2k(n+k)^2}+\frac1{nk^2(n+k)^2}\right)\\
&=\frac12\sum_{k,n=1}^\infty\frac1{n^2k^2(n+k)}\\
&=\frac12\sum_{k,n=1}^\infty\left(\frac1{n^3k^2}-\frac1{n^3k(n+k)}\right)\\
&=\frac12\zeta(2)\zeta(3)-\frac12\sum_{k,n=1}^\infty\frac1{n^4}\left(\frac1k-\frac1{n+k}\right)\\
&=\frac12\zeta(2)\zeta(3)-\frac12\sum_{n=1}^\infty\frac{H_n}{n^4}
\end{align}
$$
I got an unweighted, undirected graph, with $N$ vertices, where each vertex has degree $K$. In my case its a grid with dynamic obstacles.
My goal is to output a map, based on given location on the grid, with the shortest path to all the cells on the grid, some thing like this:
4 3 2 3
3 2 1 2
...
