17 lines
441 B
Python
17 lines
441 B
Python
from math import gcd
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def φ(n):
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return sum(1 for k in range(1, n + 1) if gcd(n, k) == 1)
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if __name__ == '__main__':
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def is_prime(n):
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return φ(n) == n - 1
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for n in range(1, 26):
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print(f" φ({n}) == {φ(n)}{', is prime' if is_prime(n) else ''}")
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count = 0
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for n in range(1, 10_000 + 1):
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count += is_prime(n)
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if n in {100, 1000, 10_000}:
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print(f"Primes up to {n}: {count}")
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