Odd Amicable Pair/Examples/31,695,652,275-33,100,200,525
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Example of Odd Amicable Pair
$31 \, 695 \, 652 \, 275$ and $33 \, 100 \, 200 \, 525$ are an odd amicable pair:
- $\map {\sigma_1} {31 \, 695 \, 652 \, 275} = \map {\sigma_1} {33 \, 100 \, 200 \, 525} = 64 \, 795 \, 852 \, 800 = 31 \, 695 \, 652 \, 275 + 33 \, 100 \, 200 \, 525$
Proof
By definition, $m$ and $n$ form an amicable pair if and only if:
- $\map {\sigma_1} m = \map {\sigma_1} n = m + n$
where $\sigma_1$ denotes the divisor sum function.
Thus:
\(\ds \map {\sigma_1} {31 \, 695 \, 652 \, 275}\) | \(=\) | \(\ds 64 \, 795 \, 852 \, 800\) | $\sigma_1$ of $31 \, 695 \, 652 \, 275$ | |||||||||||
\(\ds \) | \(=\) | \(\ds 31 \, 695 \, 652 \, 275 + 33 \, 100 \, 200 \, 525\) | ||||||||||||
\(\ds \) | \(=\) | \(\ds \map {\sigma_1} {33 \, 100 \, 200 \, 525}\) | $\sigma_1$ of $33 \, 100 \, 200 \, 525$ |
$\blacksquare$
Sources
- 1997: David Wells: Curious and Interesting Numbers (2nd ed.) ... (previous) ... (next): $64,795,852,800$