Smith Brothers/Examples/728 and 729
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Example of Smith Brothers
$728$ and $729$ are Smith brothers:
\(\ds 728\) | \(\) | \(\, \ds = \, \) | \(\ds 2^3 \times 7 \times 13\) | |||||||||||
\(\ds 7 + 2 + 8\) | \(=\) | \(\, \ds 17 \, \) | \(\, \ds = \, \) | \(\ds 2 + 2 + 2 + 7 + 1 + 3\) |
\(\ds 729\) | \(\) | \(\, \ds = \, \) | \(\ds 3^6\) | |||||||||||
\(\ds 7 + 2 + 9\) | \(=\) | \(\, \ds 18 \, \) | \(\, \ds = \, \) | \(\ds 3 + 3 + 3 + 3 + 3 + 3\) |
Sources
- 1997: David Wells: Curious and Interesting Numbers (2nd ed.) ... (previous) ... (next): $728$