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Results tagged with reference-request
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user 4313
This tag is used if a reference is needed in a paper or textbook on a specific result.
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votes
Proofs without words
Also elementary, but here is a proof that
$C_n = \binom{2n}{n} - \binom{2n}{n+1} = \frac{\binom{2n}{n}}{n+1},$
where $C_n$ is the $n$th Catalan number.
http://utdallas.edu/~hagge/images/Catalan.pdf (W …