Description: Lemma for prmrec . There are at most 2 ^ K squarefree numbers which divide no primes larger than K . (We could strengthen this to 2 ^ # ( Prime i^i ( 1 ... K ) ) but there's no reason to.) We establish the inequality by showing that the prime counts of the number up to K completely determine it because all higher prime counts are zero, and they are all at most 1 because no square divides the number, so there are at most 2 ^ K possibilities. (Contributed by Mario Carneiro, 5-Aug-2014)
Ref | Expression | ||
---|---|---|---|
Hypotheses | prmrec.1 | |
|
prmrec.2 | |
||
prmrec.3 | |
||
prmrec.4 | |
||
prmreclem2.5 | |
||
Assertion | prmreclem2 | |