If the differences of a series do not form a simple arithmetic progression, try writing each difference as a function of its index:
Common patterns include $n^2 + n$, $n^2 - n$, $n^3 + n$, or $n^3 - n^2$.
Recognizing numbers like $180$, $100$, and $48$ as near perfect cubes ($216, 125, 64$) can quickly reveal the $n^3 - n^2$ pattern.