Sieves are quick ways to yield primes, or other numbers, based on some rule of cancellation.

```
function sieve(N::Int)
U = ones(N)
U[1] = 0
for p in 2:div(N,2)
if U[p] == 1
for m in 2*p:p:N
U[m] = 0
end
end
end
U
end
```

© Daniel Marvin. Last modified: July 19, 2021.