Math — Induction & Standard Sums
The closed forms commonly proved by induction.
Rendering…
Make it your own.
\sum_{k=1}^n k = \frac{n(n+1)}{2}
\sum_{k=1}^n k^2 = \frac{n(n+1)(2n+1)}{6}
\sum_{k=1}^n k^3 = \left(\frac{n(n+1)}{2}\right)^2
\sum_{k=0}^n r^k = \frac{r^{n+1}-1}{r-1}