Talk:Best Approximation from Below to 1 as Sum of Minimal Number of Unit Fractions
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Note that:
\(\ds \paren {1}^{-1} + 1\) | \(=\) | \(\ds 2\) | |||||||||||||
\(\ds \paren {1 - \frac 1 2}^{-1} + 1\) | \(=\) | \(\ds 3\) | |||||||||||||
\(\ds \paren {1 - \frac 1 2 - \frac 1 3}^{-1} + 1\) | \(=\) | \(\ds 7\) | |||||||||||||
\(\ds \paren {1 - \frac 1 2 - \frac 1 3 - \frac 1 7}^{-1} + 1\) | \(=\) | \(\ds 43\) | |||||||||||||
and, unsurprisingly: | |||||||||||||||
\(\ds \paren {1 - \frac 1 2 - \frac 1 3 - \frac 1 7 - \frac 1 {43} }^{-1}\) | \(=\) | \(\ds 1806\) |
Best approximation as in sum of $4$ unit fractions closest to $1^-$?
Its' infinite version is the greedy Egyptian representation of $1$.
Wells is possibly hinting towards Sylvester's Sequence (is it the same one as the red link on Sylvester's page?):
- $2, 3, 7, 43, 1807, 3263443, \dots$
recursively defined by
- $a_1 = 2$, $a_n = 1 + \ds \prod_{1 \mathop \le k \mathop < n} a_k$
This sequence is A000058 in the On-Line Encyclopedia of Integer Sequences (N. J. A. Sloane (Ed.), 2008).
- --RandomUndergrad (talk) 14:22, 18 July 2020 (UTC)
- Yes, it would be that same "Sylvester's sequence" because I got the list of things named after JJS off his wikipedia page, which is indeed a direct link to that sequence.
- So I reckon what we can do with this page is either turn it into Definition:Sylvester's Sequence or a page about Definition:Sylvester's Sequence, or something.
- Feel free to make something sensible about this if you have a good idea of how to craft it. --prime mover (talk) 16:10, 18 July 2020 (UTC)