Timeline for Show that there is a number consisting only of 1’s that is divisible by 2001
Current License: CC BY-SA 4.0
6 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Jun 23, 2019 at 3:43 | comment | added | J. W. Tanner | @ChrisCuster: sorry if wasn't clear; does this help? If $a\equiv1\pmod9$ then also $a\equiv1\pmod3$ so $3|a^2+a+1$ so $27|a^3-1=(a-1)(a^2+a+1)$ ; use that with $a=10^{\phi(2001)}$ | |
| Jun 23, 2019 at 3:06 | comment | added | user403337 | Could you explain the last step? | |
| Jun 23, 2019 at 2:20 | comment | added | J. W. Tanner | so the number with $3696$ $1$s is divisible by $2001$ | |
| Jun 23, 2019 at 2:16 | history | undeleted | J. W. Tanner | ||
| Jun 23, 2019 at 2:16 | history | deleted | J. W. Tanner | via Vote | |
| Jun 23, 2019 at 2:16 | history | answered | J. W. Tanner | CC BY-SA 4.0 |