A list of cheatsheet of whatever that fits with my workflow

Big O(micron):O or OBig Omega:ΩBig Theta:ΘSmall O(micron):oSmall Omega:ωOn the order of::\begin{aligned} \text{Big O(micron)} &: O \text{ or } \mathcal{O} \\ \text{Big Omega} &: \Omega \\ \text{Big Theta} &: \Theta \\ \text{Small O(micron)} &: o \\ \text{Small Omega} &: \omega \\ \text{On the order of}: &: \sim \end{aligned}