Unclear on step #2 of the MathWorld definition of the Reimann Prime Counting Function
up vote
0
down vote
favorite
I was reading through the MathWorld article on the Reimann Prime Counting Function.
The first step in the definition is clear to me:
$$f(x) = sum_{p^v < x text{ and p prime}} frac{1}{v}$$
Here is the second step:
$$=sum_{n}frac{pi(x^{1/n})}{n}$$
It is not clear to me how the sum of the reciprocal of the power is equal to the sum of the prime counting function divided by all values of $n$.
I would appreciate if someone could show how the second step follows from the first.
prime-numbers proof-explanation
add a comment |
up vote
0
down vote
favorite
I was reading through the MathWorld article on the Reimann Prime Counting Function.
The first step in the definition is clear to me:
$$f(x) = sum_{p^v < x text{ and p prime}} frac{1}{v}$$
Here is the second step:
$$=sum_{n}frac{pi(x^{1/n})}{n}$$
It is not clear to me how the sum of the reciprocal of the power is equal to the sum of the prime counting function divided by all values of $n$.
I would appreciate if someone could show how the second step follows from the first.
prime-numbers proof-explanation
add a comment |
up vote
0
down vote
favorite
up vote
0
down vote
favorite
I was reading through the MathWorld article on the Reimann Prime Counting Function.
The first step in the definition is clear to me:
$$f(x) = sum_{p^v < x text{ and p prime}} frac{1}{v}$$
Here is the second step:
$$=sum_{n}frac{pi(x^{1/n})}{n}$$
It is not clear to me how the sum of the reciprocal of the power is equal to the sum of the prime counting function divided by all values of $n$.
I would appreciate if someone could show how the second step follows from the first.
prime-numbers proof-explanation
I was reading through the MathWorld article on the Reimann Prime Counting Function.
The first step in the definition is clear to me:
$$f(x) = sum_{p^v < x text{ and p prime}} frac{1}{v}$$
Here is the second step:
$$=sum_{n}frac{pi(x^{1/n})}{n}$$
It is not clear to me how the sum of the reciprocal of the power is equal to the sum of the prime counting function divided by all values of $n$.
I would appreciate if someone could show how the second step follows from the first.
prime-numbers proof-explanation
prime-numbers proof-explanation
asked Nov 19 at 17:00
Larry Freeman
3,24721239
3,24721239
add a comment |
add a comment |
1 Answer
1
active
oldest
votes
up vote
1
down vote
accepted
Hint:
How many $v$-th powers of primes are there between $1$ and $x$?
Answer: if $p$ is a prime then $p^v<x$ iff $p<x^{1/v}$. Then the number of $v$-th powers of primes between $1$ and $x$ is $pi(x^{1/v})$.
the product of these numbers is the least common multiple of $x$.
– Larry Freeman
Nov 19 at 17:09
Now, I am clear. Thanks!
– Larry Freeman
Nov 19 at 23:54
add a comment |
1 Answer
1
active
oldest
votes
1 Answer
1
active
oldest
votes
active
oldest
votes
active
oldest
votes
up vote
1
down vote
accepted
Hint:
How many $v$-th powers of primes are there between $1$ and $x$?
Answer: if $p$ is a prime then $p^v<x$ iff $p<x^{1/v}$. Then the number of $v$-th powers of primes between $1$ and $x$ is $pi(x^{1/v})$.
the product of these numbers is the least common multiple of $x$.
– Larry Freeman
Nov 19 at 17:09
Now, I am clear. Thanks!
– Larry Freeman
Nov 19 at 23:54
add a comment |
up vote
1
down vote
accepted
Hint:
How many $v$-th powers of primes are there between $1$ and $x$?
Answer: if $p$ is a prime then $p^v<x$ iff $p<x^{1/v}$. Then the number of $v$-th powers of primes between $1$ and $x$ is $pi(x^{1/v})$.
the product of these numbers is the least common multiple of $x$.
– Larry Freeman
Nov 19 at 17:09
Now, I am clear. Thanks!
– Larry Freeman
Nov 19 at 23:54
add a comment |
up vote
1
down vote
accepted
up vote
1
down vote
accepted
Hint:
How many $v$-th powers of primes are there between $1$ and $x$?
Answer: if $p$ is a prime then $p^v<x$ iff $p<x^{1/v}$. Then the number of $v$-th powers of primes between $1$ and $x$ is $pi(x^{1/v})$.
Hint:
How many $v$-th powers of primes are there between $1$ and $x$?
Answer: if $p$ is a prime then $p^v<x$ iff $p<x^{1/v}$. Then the number of $v$-th powers of primes between $1$ and $x$ is $pi(x^{1/v})$.
edited Nov 19 at 17:12
answered Nov 19 at 17:05
ajotatxe
52.3k23789
52.3k23789
the product of these numbers is the least common multiple of $x$.
– Larry Freeman
Nov 19 at 17:09
Now, I am clear. Thanks!
– Larry Freeman
Nov 19 at 23:54
add a comment |
the product of these numbers is the least common multiple of $x$.
– Larry Freeman
Nov 19 at 17:09
Now, I am clear. Thanks!
– Larry Freeman
Nov 19 at 23:54
the product of these numbers is the least common multiple of $x$.
– Larry Freeman
Nov 19 at 17:09
the product of these numbers is the least common multiple of $x$.
– Larry Freeman
Nov 19 at 17:09
Now, I am clear. Thanks!
– Larry Freeman
Nov 19 at 23:54
Now, I am clear. Thanks!
– Larry Freeman
Nov 19 at 23:54
add a comment |
Thanks for contributing an answer to Mathematics Stack Exchange!
- Please be sure to answer the question. Provide details and share your research!
But avoid …
- Asking for help, clarification, or responding to other answers.
- Making statements based on opinion; back them up with references or personal experience.
Use MathJax to format equations. MathJax reference.
To learn more, see our tips on writing great answers.
Some of your past answers have not been well-received, and you're in danger of being blocked from answering.
Please pay close attention to the following guidance:
- Please be sure to answer the question. Provide details and share your research!
But avoid …
- Asking for help, clarification, or responding to other answers.
- Making statements based on opinion; back them up with references or personal experience.
To learn more, see our tips on writing great answers.
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f3005185%2funclear-on-step-2-of-the-mathworld-definition-of-the-reimann-prime-counting-fun%23new-answer', 'question_page');
}
);
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown