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A082996 a(n) = card{ x <= n : bigomega(x) = 4 }. 3
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 5, 5, 6, 6, 6, 6, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 8, 8, 8, 9, 9, 9, 9, 10, 10, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,24
LINKS
Charles R Greathouse IV, Table of n, a(n) for n = 1..10000
FORMULA
a(n) ~ (1/6)*(n/log(n))*log(log(n))^3.
PROG
(PARI) a(n)=sum(i=1, n, bigomega(i)==4)
(PARI) a(n)=my(j, s); forprime(p=2, (n+.5)^(1/4), forprime(q=p, (n/p+.5)^(1/3), j=primepi(q)-2; forprime(r=q, sqrtint(n\(p*q)), s+=primepi(n\(p*q*r))-j++))); s \\ Charles R Greathouse IV, Mar 21 2012
CROSSREFS
Partial sums of A101637.
Sequence in context: A342696 A064459 A279758 * A094382 A146167 A346622
KEYWORD
nonn,easy
AUTHOR
Benoit Cloitre, May 30 2003
STATUS
approved

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Last modified March 28 09:04 EDT 2024. Contains 371240 sequences. (Running on oeis4.)