Timeline for Is there a positive odd $n$ such that $\sigma(\sigma(n)) = \sigma(\sigma(n)-n)+\sigma(n)$?
Current License: CC BY-SA 4.0
8 events
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| Jul 5, 2021 at 17:54 | history | edited | Alkan |
I added a tag which I miss past.
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| Jul 5, 2021 at 17:49 | comment | added | Alkan | I am sorry for late response. I was curious about a possible connection to conjecture on existence of an odd perfect number and such nesting argument that question focuses on. So I wanted to share my observation on sequence entry and increase my knowledge on the subject. Best regards. | |
| Sep 6, 2020 at 7:48 | comment | added | Jose Arnaldo Bebita | @Alkan: What is your motivation for pursuing a solution to this problem? | |
| Aug 4, 2020 at 16:35 | comment | added | Alkan | Thanks for your computation. It is noted that it is greater than $2.10^{11}$, if such $n$ exists. | |
| Aug 4, 2020 at 14:35 | comment | added | Greg Hurst | The only such $n$ less than $5.7\cdot10^9$ are all even: $2, 38040, 51888, 236644, 260880, 3097024, 5283852, 5667312, 11777472, 46120848, 52981252, 69128640, 121352208, 330364848, 485906400, 662736600, 769422720, 1111869360, 1267978320, 1272335760, 1426817904, 1807128528, 2107406448, 2381691312, 2452404544, 2691587568, 3758996016, 4403660352, 5139308592.$ | |
| Aug 4, 2020 at 7:59 | history | edited | Alkan | CC BY-SA 4.0 |
added 7 characters in body; edited title
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| Aug 4, 2020 at 7:49 | history | edited | Alkan | CC BY-SA 4.0 |
added 18 characters in body
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| Aug 4, 2020 at 7:40 | history | asked | Alkan | CC BY-SA 4.0 |