Sieve of Eratosthenes

Primes.kt

// https://en.wikipedia.org/wiki/Sieve_of_Eratosthenes
val primes: Sequence<Int> = sequence {
    var numbers = generateSequence(2) { it + 1 }

    while (true) {
        val prime = numbers.first()
        yield(prime)
        numbers = numbers
                .drop(1)
                .filter { it % prime != 0 }
    }
} // works
primes.take(10).toList()
// 2, 3, 5, 7, 11, 13, 17, 19, 23, 29

val primes2: Sequence<Int> = sequence {
    var numbers = generateSequence(2) { it + 1 }

    var prime: Int
    while (true) {
        prime = numbers.first()
        yield(prime)
        numbers = numbers
                .drop(1)
                .filter { it % prime != 0 }
    }
} // does not work
primes2.take(10).toList()
// 2, 3, 5, 6, 7, 8, 9, 10, 11, 12