Hackers' Pub

Syntax	Description	Examples
`"` keyword `"`	Finds the string within quotes, including spaces. Case-insensitive. (Escape quotes inside with `\"`)	`"Hackers' Pub"`
`from:` handle	Finds content written by the specified user.	`from:hongminhee` `from:hongminhee@hollo.social`
`lang:` ISO 639-1	Finds content written in the specified language.	`lang:en`
`#` tag	Finds content with the specified tag. Case-insensitive.	`#HackersPub`
condition condition	Finds content that satisfies both conditions on either side of the space (logical AND).	`"Hackers' Pub" lang:en`
condition `OR` condition	Finds content that satisfies at least one of the conditions on either side of the OR operator (logical OR).	`#HackersPub OR "Hackers' Pub" lang:en`
`(` condition `)`	Combines the operators within the parentheses first.	`(#HackersPub OR "Hackers' Pub" OR "Hackers Pub") lang:en`

이하 @evenharder@hackers.pub

1/6/2026, 2:08:03 AM

Public

2026년 1월 6일

오일러 피 함수 $\varphi(n)$ 의 흥미로운 예시 중 하나이다. 666보다 작으면서 666과 서로소인 양의 정수의 개수는 $\varphi(666) = 216$ 개이다. 우연히도 이는 $6 \cdot 6 \cdot 6$ 과 같다.

Euler's totient function - Wikipedia

en.wikipedia.org

이하 @evenharder@hackers.pub

1/7/2026, 2:35:23 PM

Public

2026년 1월 7일

Mochalov's Seven 7s라는 충식산(蟲食算) 문제이다.

     ..7..
   * .....
----------
    .7....
    ....7
  77....
  .....
....7.
----------
........7.

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