Erdős–Nicolas number
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| Named after | Paul Erdős, Jean-Louis Nicolas |
|---|---|
| Publication year | 1975 |
| Author of publication | Erdős, P., Nicolas, J. L. |
| Subsequence of | Abundant numbers |
| First terms | 24, 2016, 8190 |
| Largest known term | 3304572752464376776401640967110656 |
| OEIS index |
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In number theory, an Erdős–Nicolas number is a number that is not perfect, but that equals one of the partial sums of its divisors. That is, a number n is an Erdős–Nicolas number when there exists another number m such that
- [math]\displaystyle{ \sum_{d\mid n,\ d\leq m}d=n. }[/math][1]
The first ten Erdős–Nicolas numbers are
They are named after Paul Erdős and Jean-Louis Nicolas, who wrote about them in 1975.[2]
See also
- Descartes number, another type of almost-perfect numbers
References
- ↑ De Koninck, Jean-Marie (2009). Those Fascinating Numbers. p. 141. ISBN 978-0-8218-4807-4. https://www.ams.org/bookpages/mbk-64.
- ↑ "Répartition des nombres superabondants", Bull. Soc. Math. France 79 (103): 65–90, 1975, doi:10.24033/bsmf.1793, http://archive.numdam.org/article/BSMF_1975__103__65_0.pdf
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| Aliquot sequence-related | ||
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