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 A094757 Least k <= n such that n*pi(k) = k*pi(n), where pi(n) is the number of primes <= n (A000720). 3
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 OFFSET 1,2 COMMENTS Conjecture: For every n there exists a k different from n (possibly k > n) such that n*pi(k) = k*pi(n). (Amarnath Murthy) LINKS EXAMPLE a(15) = 10 as 15*pi(10) = 15*4 = 60 = 10*pi(15) = 10*6. PROG (PARI) {m=72; pi=vector(m, n, omega(n!)); for(n=1, m, k=1; while(n*pi[k]!=k*pi[n], k++); print1(k, ", "))} CROSSREFS Cf. A095299 for n such that a(n) < n. Cf. A000720, A094758, A094759. Sequence in context: A007387 A105222 A280503 * A095171 A270443 A096776 Adjacent sequences:  A094754 A094755 A094756 * A094758 A094759 A094760 KEYWORD nonn AUTHOR Amarnath Murthy, May 30 2004 EXTENSIONS Edited and extended by Klaus Brockhaus, Jun 01 2004 STATUS approved

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