Prime Sieve
Interactions
- Click a number on the sieve: the strokes that hit it are traced again, one pass per prime factor, and its factorisation is written beside it
- Click a prime: its red ring is inked again and a small flourish curls off it
- Drag across the spiral to change its starting number; at 41 Euler's n² + n + 41 shows as one long diagonal
- Click the staircase to extend the range tenfold (up to 100 000, then back to 100)