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A140234 Sum of the semiprimes <= n. 1
0, 0, 0, 0, 4, 4, 10, 10, 10, 19, 29, 29, 29, 29, 43, 58, 58, 58, 58, 58, 58, 79, 101, 101, 101, 126, 152, 152, 152, 152, 152, 152, 152, 185, 219, 254, 254, 254, 292, 331, 331, 331, 331, 331, 331, 331, 377, 377, 377, 426, 426, 477, 477, 477, 477, 532, 532, 589 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,5
COMMENTS
This is to semiprimes A001358 as A034387 is to primes A000040. From the prime number theorem A034387(n) has the asymptotic expression: a(n) ~ n^2 / (2 log n), so what is the asymptotic expression for a(n)?
LINKS
FORMULA
a(n) = Sum_{j such that j is in A001358 and j<=n} = A062198(A072000(n)).
CROSSREFS
Sequence in context: A134637 A078910 A196051 * A220044 A219828 A219714
KEYWORD
easy,nonn
AUTHOR
Jonathan Vos Post, May 13 2008
STATUS
approved

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Last modified July 25 05:51 EDT 2024. Contains 374586 sequences. (Running on oeis4.)