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 A064775 Card{ k<=n, k such that all prime divisors of k are <= sqrt(k) }. 1
 1, 1, 1, 2, 2, 2, 2, 3, 4, 4, 4, 5, 5, 5, 5, 6, 6, 7, 7, 7, 7, 7, 7, 8, 9, 9, 10, 10, 10, 11, 11, 12, 12, 12, 12, 13, 13, 13, 13, 14, 14, 14, 14, 14, 15, 15, 15, 16, 17, 18, 18, 18, 18, 19, 19, 20, 20, 20, 20, 21, 21, 21, 22, 23, 23, 23, 23, 23, 23, 24, 24, 25, 25, 25, 26, 26, 26, 26 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,4 COMMENTS A048098(n) is the n-th number k such that all prime divisors of k are <= sqrt(k). REFERENCES D. P. Parent, Exercices de theorie des nombres, Les grands classiques, Gauthier-Villars, Edition Jacques Gabay, p. 17 LINKS Harry J. Smith, Table of n, a(n) for n=1..1000 FORMULA a(n)=n-sum(p<=sqrt(n), (p-1))-sum(sqrt(n)

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Last modified October 22 08:00 EDT 2019. Contains 328315 sequences. (Running on oeis4.)