Énigme pour Alexis. Que fait ce script ?

énigme.py

#!/usr/bin/env python3

import sqlite3

conn = sqlite3.connect(":memory:");
cur = conn.cursor()

cur.execute("CREATE TABLE IF NOT EXISTS nums(n INTEGER PRIMARY KEY)");
cur.executemany("INSERT INTO nums VALUES (?)", ((i,) for i in range(1,1000)));
cur.execute("DELETE FROM nums WHERE (SELECT COUNT(n2.n)>2 FROM nums AS n2 WHERE nums.n%n2.n=0)");
for (n,) in cur.execute("SELECT * FROM nums"): print(n, end=' ')