HowStuffWorks - Learn How Everything Works!

First 25 Perfect Squares Quiz

Number theory Square perfect numbers gif stack sum theory exchange number adjacent

HowStuffWorks - Learn How Everything Works!

HowStuffWorks - Learn How Everything Works!
HowStuffWorks - Learn How Everything Works!

number theory - For which $n$ can $\{1,2,...,n\}$ be rearranged so that
number theory - For which $n$ can $\{1,2,...,n\}$ be rearranged so that