Numbers whose Divisor Sum is Square/Examples/3

Example of Number whose Divisor Sum is Square

$\map {\sigma_1} 3 = 4 = 2^2$

Proof

\(\ds \map {\sigma_1} 3\)

\(=\)

\(\ds 3 + 1\)

$\sigma_1$ of $3$

\(\ds \)

\(=\)

\(\ds 4\)

\(\ds \)

\(=\)

\(\ds 2^2\)

$\blacksquare$