How many integers whose total number of prime factors is prime are there below x?












3












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Let $ Omega(n) $ be the total number of prime factors of a positive integer $ n $. Denote by $mathbb{P}_{Omega}(x) $ the number of positive integers $ n $ not exceeding $ x $ such that $ Omega(n)inmathbb{P} $. Is an upper bound for this function known ? If yes, is the fact that all non trivial partitions of a prime contain at least $ 2 $ distinct summands anyhow used in establishing this upper bound ?










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$endgroup$












  • $begingroup$
    $P_{Omega}(x,0)$ in here mathoverflow.net/questions/297785/…
    $endgroup$
    – Collag3n
    Dec 31 '18 at 21:04












  • $begingroup$
    Thank but I think in that link $ k $ is a number while I meant $ mathbb{A}_{f}(x) $ with $ f $ a function to denote the number of positive integers $ n $ below $ x $ such that the numbers $ f(n) $ belong to the set $ mathbb{A} $ .
    $endgroup$
    – Sylvain Julien
    Dec 31 '18 at 21:43












  • $begingroup$
    That way, $ pi(x) $ is $ mathbb{P}_{Id}(x) $ .
    $endgroup$
    – Sylvain Julien
    Dec 31 '18 at 21:48






  • 1




    $begingroup$
    Ok, so $P_{Omega}(x) = P_2(x,0) + P_3(x,0) + P_5(x,0) + P_7(x,0)....$ up to max $P_{lfloor log_{p_{(a+1)}}(x) rfloor}(x,0)$ ?
    $endgroup$
    – Collag3n
    Dec 31 '18 at 21:59








  • 1




    $begingroup$
    up to $x=15$ this is exactly $x-pi(x)-1$
    $endgroup$
    – Collag3n
    Dec 31 '18 at 23:11


















3












$begingroup$


Let $ Omega(n) $ be the total number of prime factors of a positive integer $ n $. Denote by $mathbb{P}_{Omega}(x) $ the number of positive integers $ n $ not exceeding $ x $ such that $ Omega(n)inmathbb{P} $. Is an upper bound for this function known ? If yes, is the fact that all non trivial partitions of a prime contain at least $ 2 $ distinct summands anyhow used in establishing this upper bound ?










share|cite|improve this question









$endgroup$












  • $begingroup$
    $P_{Omega}(x,0)$ in here mathoverflow.net/questions/297785/…
    $endgroup$
    – Collag3n
    Dec 31 '18 at 21:04












  • $begingroup$
    Thank but I think in that link $ k $ is a number while I meant $ mathbb{A}_{f}(x) $ with $ f $ a function to denote the number of positive integers $ n $ below $ x $ such that the numbers $ f(n) $ belong to the set $ mathbb{A} $ .
    $endgroup$
    – Sylvain Julien
    Dec 31 '18 at 21:43












  • $begingroup$
    That way, $ pi(x) $ is $ mathbb{P}_{Id}(x) $ .
    $endgroup$
    – Sylvain Julien
    Dec 31 '18 at 21:48






  • 1




    $begingroup$
    Ok, so $P_{Omega}(x) = P_2(x,0) + P_3(x,0) + P_5(x,0) + P_7(x,0)....$ up to max $P_{lfloor log_{p_{(a+1)}}(x) rfloor}(x,0)$ ?
    $endgroup$
    – Collag3n
    Dec 31 '18 at 21:59








  • 1




    $begingroup$
    up to $x=15$ this is exactly $x-pi(x)-1$
    $endgroup$
    – Collag3n
    Dec 31 '18 at 23:11
















3












3








3





$begingroup$


Let $ Omega(n) $ be the total number of prime factors of a positive integer $ n $. Denote by $mathbb{P}_{Omega}(x) $ the number of positive integers $ n $ not exceeding $ x $ such that $ Omega(n)inmathbb{P} $. Is an upper bound for this function known ? If yes, is the fact that all non trivial partitions of a prime contain at least $ 2 $ distinct summands anyhow used in establishing this upper bound ?










share|cite|improve this question









$endgroup$




Let $ Omega(n) $ be the total number of prime factors of a positive integer $ n $. Denote by $mathbb{P}_{Omega}(x) $ the number of positive integers $ n $ not exceeding $ x $ such that $ Omega(n)inmathbb{P} $. Is an upper bound for this function known ? If yes, is the fact that all non trivial partitions of a prime contain at least $ 2 $ distinct summands anyhow used in establishing this upper bound ?







number-theory prime-numbers






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share|cite|improve this question











share|cite|improve this question




share|cite|improve this question










asked Dec 31 '18 at 20:00









Sylvain JulienSylvain Julien

1,150918




1,150918












  • $begingroup$
    $P_{Omega}(x,0)$ in here mathoverflow.net/questions/297785/…
    $endgroup$
    – Collag3n
    Dec 31 '18 at 21:04












  • $begingroup$
    Thank but I think in that link $ k $ is a number while I meant $ mathbb{A}_{f}(x) $ with $ f $ a function to denote the number of positive integers $ n $ below $ x $ such that the numbers $ f(n) $ belong to the set $ mathbb{A} $ .
    $endgroup$
    – Sylvain Julien
    Dec 31 '18 at 21:43












  • $begingroup$
    That way, $ pi(x) $ is $ mathbb{P}_{Id}(x) $ .
    $endgroup$
    – Sylvain Julien
    Dec 31 '18 at 21:48






  • 1




    $begingroup$
    Ok, so $P_{Omega}(x) = P_2(x,0) + P_3(x,0) + P_5(x,0) + P_7(x,0)....$ up to max $P_{lfloor log_{p_{(a+1)}}(x) rfloor}(x,0)$ ?
    $endgroup$
    – Collag3n
    Dec 31 '18 at 21:59








  • 1




    $begingroup$
    up to $x=15$ this is exactly $x-pi(x)-1$
    $endgroup$
    – Collag3n
    Dec 31 '18 at 23:11




















  • $begingroup$
    $P_{Omega}(x,0)$ in here mathoverflow.net/questions/297785/…
    $endgroup$
    – Collag3n
    Dec 31 '18 at 21:04












  • $begingroup$
    Thank but I think in that link $ k $ is a number while I meant $ mathbb{A}_{f}(x) $ with $ f $ a function to denote the number of positive integers $ n $ below $ x $ such that the numbers $ f(n) $ belong to the set $ mathbb{A} $ .
    $endgroup$
    – Sylvain Julien
    Dec 31 '18 at 21:43












  • $begingroup$
    That way, $ pi(x) $ is $ mathbb{P}_{Id}(x) $ .
    $endgroup$
    – Sylvain Julien
    Dec 31 '18 at 21:48






  • 1




    $begingroup$
    Ok, so $P_{Omega}(x) = P_2(x,0) + P_3(x,0) + P_5(x,0) + P_7(x,0)....$ up to max $P_{lfloor log_{p_{(a+1)}}(x) rfloor}(x,0)$ ?
    $endgroup$
    – Collag3n
    Dec 31 '18 at 21:59








  • 1




    $begingroup$
    up to $x=15$ this is exactly $x-pi(x)-1$
    $endgroup$
    – Collag3n
    Dec 31 '18 at 23:11


















$begingroup$
$P_{Omega}(x,0)$ in here mathoverflow.net/questions/297785/…
$endgroup$
– Collag3n
Dec 31 '18 at 21:04






$begingroup$
$P_{Omega}(x,0)$ in here mathoverflow.net/questions/297785/…
$endgroup$
– Collag3n
Dec 31 '18 at 21:04














$begingroup$
Thank but I think in that link $ k $ is a number while I meant $ mathbb{A}_{f}(x) $ with $ f $ a function to denote the number of positive integers $ n $ below $ x $ such that the numbers $ f(n) $ belong to the set $ mathbb{A} $ .
$endgroup$
– Sylvain Julien
Dec 31 '18 at 21:43






$begingroup$
Thank but I think in that link $ k $ is a number while I meant $ mathbb{A}_{f}(x) $ with $ f $ a function to denote the number of positive integers $ n $ below $ x $ such that the numbers $ f(n) $ belong to the set $ mathbb{A} $ .
$endgroup$
– Sylvain Julien
Dec 31 '18 at 21:43














$begingroup$
That way, $ pi(x) $ is $ mathbb{P}_{Id}(x) $ .
$endgroup$
– Sylvain Julien
Dec 31 '18 at 21:48




$begingroup$
That way, $ pi(x) $ is $ mathbb{P}_{Id}(x) $ .
$endgroup$
– Sylvain Julien
Dec 31 '18 at 21:48




1




1




$begingroup$
Ok, so $P_{Omega}(x) = P_2(x,0) + P_3(x,0) + P_5(x,0) + P_7(x,0)....$ up to max $P_{lfloor log_{p_{(a+1)}}(x) rfloor}(x,0)$ ?
$endgroup$
– Collag3n
Dec 31 '18 at 21:59






$begingroup$
Ok, so $P_{Omega}(x) = P_2(x,0) + P_3(x,0) + P_5(x,0) + P_7(x,0)....$ up to max $P_{lfloor log_{p_{(a+1)}}(x) rfloor}(x,0)$ ?
$endgroup$
– Collag3n
Dec 31 '18 at 21:59






1




1




$begingroup$
up to $x=15$ this is exactly $x-pi(x)-1$
$endgroup$
– Collag3n
Dec 31 '18 at 23:11






$begingroup$
up to $x=15$ this is exactly $x-pi(x)-1$
$endgroup$
– Collag3n
Dec 31 '18 at 23:11












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