The digit inside a sweeper square says how many of the digits within a king's move of it (including itself) are in the set of numbers created by the well known mathematical sequence specified (eg Primes, Fibonacci numbers, Square numbers, etc)
Example Puzzle:
Fibonacci Sweeper (4916 in CTC discord archive)
Primesweeper: Civil War (1474 in CTC discord archive)
Rules:
The digit inside a sweeper square says how many of the digits within a king's move of it (including itself) are in the set of numbers created by the well known mathematical sequence specified (eg Primes, Fibonacci numbers, Square numbers, etc)
Example Puzzle:
Fibonacci Sweeper (4916 in CTC discord archive) Primesweeper: Civil War (1474 in CTC discord archive)
Userscript implementation:
https://github.com/louisereay/fPuzzles/wiki