Description: There is a bijection from the squarefree divisors of a number N to the powerset of the prime divisors of N . Among other things, this implies that a number has 2 ^ k squarefree divisors where k is the number of prime divisors, and a squarefree number has 2 ^ k divisors (because all divisors of a squarefree number are squarefree). The inverse function to F takes the product of all the primes in some subset of prime divisors of N . (Contributed by Mario Carneiro, 1-Jul-2015)
Ref | Expression | ||
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Hypotheses | sqff1o.1 | |
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sqff1o.2 | |
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sqff1o.3 | |
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Assertion | sqff1o | |