A simple algorithm to prime factorization
$begingroup$
Here a proff:
We know that:
$n!=prod_{P_{i} leq n}p_{i}^{ alpha_{i}(n)}$; where:
$alpha_{i}(n)=sum_{t=1}^{r}[frac{n}{p_{i}^{t}}]$ and $p^{r} leq n < p^{r+1}$.
Then:
$n=frac {n!}{(n-1)!}=prod_{P_{i} leq n}p_{i}^{ beta_{i}(n)}$ (Eq. 1)
Where:
$beta_{i}(n)= alpha_{i}(n)-alpha_{i}(n-1)$
In other words, this method can be used also to found a relation between the prime factirization of n+1 from n, lets see:
$n+1=prod_{P_{i} leq n+1}p_{i}^{ beta_{i}(n+1)}$; where:
$beta_{i}(n+1)= alpha_{i}(n+1)-alpha_{i}(n)$.
Finally, this is the relation:
$beta_{i}(n+1)= alpha_{i}(n+1)-alpha_{i}(n-1)-beta_{i}(n)$.
Example of prime factorization whit this method:
$n=60$
$beta_{i}(60)=sum_{t}^{r} {[frac {60}{p_{i}^{t}}]-[frac {59}{p_{i}^{t}}]}$
Then:
$beta_{1}(60)=sum_{t}^{r} {[frac {60}{2^{t}}]-[frac {59}{2^{t}}]}=2$
$beta_{2}(60)=sum_{t}^{r} {[frac {60}{3^{t}}]-[frac {59}{3^{t}}]}=1$
$beta_{1}(60)=sum_{t}^{r} {[frac {60}{5^{t}}]-[frac {59}{5^{t}}]}=1$
Finally:
$60=2^{2}3^{1}5^{1}$
number-theory
$endgroup$
add a comment |
$begingroup$
Here a proff:
We know that:
$n!=prod_{P_{i} leq n}p_{i}^{ alpha_{i}(n)}$; where:
$alpha_{i}(n)=sum_{t=1}^{r}[frac{n}{p_{i}^{t}}]$ and $p^{r} leq n < p^{r+1}$.
Then:
$n=frac {n!}{(n-1)!}=prod_{P_{i} leq n}p_{i}^{ beta_{i}(n)}$ (Eq. 1)
Where:
$beta_{i}(n)= alpha_{i}(n)-alpha_{i}(n-1)$
In other words, this method can be used also to found a relation between the prime factirization of n+1 from n, lets see:
$n+1=prod_{P_{i} leq n+1}p_{i}^{ beta_{i}(n+1)}$; where:
$beta_{i}(n+1)= alpha_{i}(n+1)-alpha_{i}(n)$.
Finally, this is the relation:
$beta_{i}(n+1)= alpha_{i}(n+1)-alpha_{i}(n-1)-beta_{i}(n)$.
Example of prime factorization whit this method:
$n=60$
$beta_{i}(60)=sum_{t}^{r} {[frac {60}{p_{i}^{t}}]-[frac {59}{p_{i}^{t}}]}$
Then:
$beta_{1}(60)=sum_{t}^{r} {[frac {60}{2^{t}}]-[frac {59}{2^{t}}]}=2$
$beta_{2}(60)=sum_{t}^{r} {[frac {60}{3^{t}}]-[frac {59}{3^{t}}]}=1$
$beta_{1}(60)=sum_{t}^{r} {[frac {60}{5^{t}}]-[frac {59}{5^{t}}]}=1$
Finally:
$60=2^{2}3^{1}5^{1}$
number-theory
$endgroup$
4
$begingroup$
What is your question? And what is the point of your proposed algorithm? It involves much more work to calculate what you call $alpha_i(n)$ than it does to calculate $beta_i(n)$ via a naive method (trial division).
$endgroup$
– Rob Arthan
Dec 4 '18 at 23:41
$begingroup$
If you expect that for large numbers , there is a relation between the factorizations of $N$ and $N+1$ that allows quick factorization, if we know the factorizaion of one of the numbers, I must disappoint you.
$endgroup$
– Peter
Dec 5 '18 at 13:05
add a comment |
$begingroup$
Here a proff:
We know that:
$n!=prod_{P_{i} leq n}p_{i}^{ alpha_{i}(n)}$; where:
$alpha_{i}(n)=sum_{t=1}^{r}[frac{n}{p_{i}^{t}}]$ and $p^{r} leq n < p^{r+1}$.
Then:
$n=frac {n!}{(n-1)!}=prod_{P_{i} leq n}p_{i}^{ beta_{i}(n)}$ (Eq. 1)
Where:
$beta_{i}(n)= alpha_{i}(n)-alpha_{i}(n-1)$
In other words, this method can be used also to found a relation between the prime factirization of n+1 from n, lets see:
$n+1=prod_{P_{i} leq n+1}p_{i}^{ beta_{i}(n+1)}$; where:
$beta_{i}(n+1)= alpha_{i}(n+1)-alpha_{i}(n)$.
Finally, this is the relation:
$beta_{i}(n+1)= alpha_{i}(n+1)-alpha_{i}(n-1)-beta_{i}(n)$.
Example of prime factorization whit this method:
$n=60$
$beta_{i}(60)=sum_{t}^{r} {[frac {60}{p_{i}^{t}}]-[frac {59}{p_{i}^{t}}]}$
Then:
$beta_{1}(60)=sum_{t}^{r} {[frac {60}{2^{t}}]-[frac {59}{2^{t}}]}=2$
$beta_{2}(60)=sum_{t}^{r} {[frac {60}{3^{t}}]-[frac {59}{3^{t}}]}=1$
$beta_{1}(60)=sum_{t}^{r} {[frac {60}{5^{t}}]-[frac {59}{5^{t}}]}=1$
Finally:
$60=2^{2}3^{1}5^{1}$
number-theory
$endgroup$
Here a proff:
We know that:
$n!=prod_{P_{i} leq n}p_{i}^{ alpha_{i}(n)}$; where:
$alpha_{i}(n)=sum_{t=1}^{r}[frac{n}{p_{i}^{t}}]$ and $p^{r} leq n < p^{r+1}$.
Then:
$n=frac {n!}{(n-1)!}=prod_{P_{i} leq n}p_{i}^{ beta_{i}(n)}$ (Eq. 1)
Where:
$beta_{i}(n)= alpha_{i}(n)-alpha_{i}(n-1)$
In other words, this method can be used also to found a relation between the prime factirization of n+1 from n, lets see:
$n+1=prod_{P_{i} leq n+1}p_{i}^{ beta_{i}(n+1)}$; where:
$beta_{i}(n+1)= alpha_{i}(n+1)-alpha_{i}(n)$.
Finally, this is the relation:
$beta_{i}(n+1)= alpha_{i}(n+1)-alpha_{i}(n-1)-beta_{i}(n)$.
Example of prime factorization whit this method:
$n=60$
$beta_{i}(60)=sum_{t}^{r} {[frac {60}{p_{i}^{t}}]-[frac {59}{p_{i}^{t}}]}$
Then:
$beta_{1}(60)=sum_{t}^{r} {[frac {60}{2^{t}}]-[frac {59}{2^{t}}]}=2$
$beta_{2}(60)=sum_{t}^{r} {[frac {60}{3^{t}}]-[frac {59}{3^{t}}]}=1$
$beta_{1}(60)=sum_{t}^{r} {[frac {60}{5^{t}}]-[frac {59}{5^{t}}]}=1$
Finally:
$60=2^{2}3^{1}5^{1}$
number-theory
number-theory
asked Dec 4 '18 at 23:32
Mauricio AreizaMauricio Areiza
143
143
4
$begingroup$
What is your question? And what is the point of your proposed algorithm? It involves much more work to calculate what you call $alpha_i(n)$ than it does to calculate $beta_i(n)$ via a naive method (trial division).
$endgroup$
– Rob Arthan
Dec 4 '18 at 23:41
$begingroup$
If you expect that for large numbers , there is a relation between the factorizations of $N$ and $N+1$ that allows quick factorization, if we know the factorizaion of one of the numbers, I must disappoint you.
$endgroup$
– Peter
Dec 5 '18 at 13:05
add a comment |
4
$begingroup$
What is your question? And what is the point of your proposed algorithm? It involves much more work to calculate what you call $alpha_i(n)$ than it does to calculate $beta_i(n)$ via a naive method (trial division).
$endgroup$
– Rob Arthan
Dec 4 '18 at 23:41
$begingroup$
If you expect that for large numbers , there is a relation between the factorizations of $N$ and $N+1$ that allows quick factorization, if we know the factorizaion of one of the numbers, I must disappoint you.
$endgroup$
– Peter
Dec 5 '18 at 13:05
4
4
$begingroup$
What is your question? And what is the point of your proposed algorithm? It involves much more work to calculate what you call $alpha_i(n)$ than it does to calculate $beta_i(n)$ via a naive method (trial division).
$endgroup$
– Rob Arthan
Dec 4 '18 at 23:41
$begingroup$
What is your question? And what is the point of your proposed algorithm? It involves much more work to calculate what you call $alpha_i(n)$ than it does to calculate $beta_i(n)$ via a naive method (trial division).
$endgroup$
– Rob Arthan
Dec 4 '18 at 23:41
$begingroup$
If you expect that for large numbers , there is a relation between the factorizations of $N$ and $N+1$ that allows quick factorization, if we know the factorizaion of one of the numbers, I must disappoint you.
$endgroup$
– Peter
Dec 5 '18 at 13:05
$begingroup$
If you expect that for large numbers , there is a relation between the factorizations of $N$ and $N+1$ that allows quick factorization, if we know the factorizaion of one of the numbers, I must disappoint you.
$endgroup$
– Peter
Dec 5 '18 at 13:05
add a comment |
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$begingroup$
What is your question? And what is the point of your proposed algorithm? It involves much more work to calculate what you call $alpha_i(n)$ than it does to calculate $beta_i(n)$ via a naive method (trial division).
$endgroup$
– Rob Arthan
Dec 4 '18 at 23:41
$begingroup$
If you expect that for large numbers , there is a relation between the factorizations of $N$ and $N+1$ that allows quick factorization, if we know the factorizaion of one of the numbers, I must disappoint you.
$endgroup$
– Peter
Dec 5 '18 at 13:05