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 A082998 a(n) = card{ x <= n : omega(x) = 3 }. 0
 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5, 5, 5, 5, 5, 6, 6, 6, 6, 6, 6, 7, 7, 7, 7, 7, 7, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 9, 9, 9, 10 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,42 REFERENCES G. Tenenbaum, Introduction à la théorie analytique et probabiliste des nombres, p. 203, Publications de l'Institut Cartan, 1990. LINKS FORMULA a(n) ~ (1/2)*(n/log(n))*log(log(n))^2. PROG (PARI) a(n)=sum(i=1, n, if(omega(i)-3, 0, 1)) CROSSREFS Cf. A025528, A072000. Sequence in context: A217693 A204560 A135661 * A076620 A121900 A287866 Adjacent sequences:  A082995 A082996 A082997 * A082999 A083000 A083001 KEYWORD nonn AUTHOR Benoit Cloitre, May 30 2003 STATUS approved

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Last modified January 28 00:32 EST 2020. Contains 331313 sequences. (Running on oeis4.)