func genPrimes(n int) []bool {

func genPrimesE(n int) []bool {

// genPrimesAtkin generates the sieve usint Atkin's method. Returns true for primes.
// https://www.geeksforgeeks.org/sieve-of-atkin/
func genPrimesAtkin(limit int) []bool {
	sieve := make([]bool, limit+1)
	// Atkin do not care about these, set them manually
	sieve[2] = true
	sieve[3] = true

	for x := 1; x*x < limit; x++ {
		for y := 1; y*y < limit; y++ {
			n := (4 * x * x) + (y * y)
			if n <= limit && (n%12 == 1 || n%12 == 5) {
				sieve[n] = !sieve[n]
			}
			n = (3 * x * x) + (y * y)
			if n <= limit && n%12 == 7 {
				sieve[n] = !sieve[n]
			}
			n = (3 * x * x) - (y * y)
			if x > y && n <= limit && n%12 == 11 {
				sieve[n] = !sieve[n]
			}
		}
	}
	for r := 5; r*r < limit; r++ {
		if sieve[r] {
			for i := r * r; i < limit; i += r * r {
				sieve[i] = false
			}
		}
	}
	return sieve
}

	var mysieve = genPrimes(MAX)

	var mysieve = genPrimesAtkin(MAX)

	count, i := 0, 0
	for i = 2; count < n; i++ {
		if !mysieve[i] {

	i := 2
	for count := 0; count < n; i++ {
		if mysieve[i] { // this was !mysieve[i] with Erastothenes