The other day I ran across a very nice video from Numberphile in YouTube, which proves that the following formula is approximate to $e$ by $18457734525360901453873570$ digits, which is pretty amazing.
\begin{align*} \left(1+9^{-4^{7\cdot 6}}\right)^{3^{2^{85}}} \approx e \end{align*}
I got excited about this, and thought about writing an article for my school magazine. Does anyone know any good references (articles, books, videos) that have interesting facts and curiosities concerning pandigital numbers and formulas?
Maybe something like the topic addressed in this this question is interesting as well, computing algorithms to find pandigital formulas...
Thanks in advance,
Miguel