Euler's relation below combines the two transcendental numbers
e and $\pi$ ,
the imaginary unit i, the multiplicative unit 1
as well as the additive unit 0
in a single equation.
Euler's Formula
$$\Large{e^{i\,\pi} + 1 = 0}$$
Negative powers of 2
$$\Large{k\in\mathbb{N}\land k > 0}$$
$$
\Large{
\begin{align}
2^{-(2\, k + 1)} &= 0....125\\
2^{-(2\, k + 2)} &= 0....625
\end{align}}
$$