PARI's commands - Page 28

CRGreathouse · 2010-08-12, 13:43

Quote:

Originally Posted by science_man_88

$24m= 6tp+(p-7)\right m=px+c$
$24m=6tp-(p+7)\right m=px+c ?$

If 24m + 7 is composite...

Quote:

Originally Posted by science_man_88

$if(px+c==(4^n-1)/3,(4^\strike n -1)/3$

What does the $,(4^\strike n -1)/3$ mean?

Quote:

Originally Posted by science_man_88

for all remaining n that create primes print(2*n+3) these are Mersenne prime exponents.

For all n such that *what* is a prime? 2n + 3?

science_man_88 · 2010-08-12, 13:52

Quote:

Originally Posted by CRGreathouse

If 24m + 7 is composite...

What does the $,(4^ \strike n -1)/3$ mean?

For all n such that *what* is a prime?

(4^n-1)/3 is the equation for A002450

that's what it was supposed to be then $\strike n$ (indexes) that are caught by px+c

what indexes are left over that give prime = 2*index+3 those should if my idea is flawless (never going to happen i'm guessing) be the indexes z such that $2^z-1$ are prime and in this case = Mersenne primes.

CRGreathouse · 2010-08-12, 13:58

Quote:

Originally Posted by science_man_88

(4^n-1)/3 is the equation for A002450

that's what it was supposed to be then $\strike n$ (indexes) that are caught by px+c

what indexes are left over that give prime = 2*index+3 those should if my idea is flawless (never going to happen i'm guessing) be the indexes z such that $2^z-1$ are prime and in this case = Mersenne primes.

Not following. I understand equations like
$px+c=(4^n-1)/3$
but
$px+c=(4^n-1)/3,(4^\strike n -1)/3$
doesn't mean anything to me.

science_man_88 · 2010-08-12, 14:04

Quote:

Originally Posted by CRGreathouse

Not following. I understand equations like
$px+c=(4^n-1)/3$
but
$px+c=(4^n-1)/3,(4^ \strike n -1)/3$
doesn't mean anything to me.

I was showing striking out the n in the first part with the second part for some reason it prints (4n-1)/3 even though i want n as a striked out exponent and I thought i coded as so.

CRGreathouse · 2010-08-12, 14:06

Quote:

Originally Posted by science_man_88

I was striking out the n in the first part with the second for some reason it prints (4n-1)/3 even though i want n as a striked out exponent and I though i coded as so.

Uh...

Apparently you want do display something, I'm not sure exactly what (the n or the whole part with the n?), with a strike-through. But I don't know what a strike-through would mean in mathematics anyway, so I don't know what the equation is supposed to be.

Similarly, what does the comma mean?

science_man_88 · 2010-08-12, 14:10

Quote:

Originally Posted by CRGreathouse

Uh...

Apparently you want do display something, I'm not sure exactly what (the n or the whole part with the n?), with a strike-through. But I don't know what a strike-through would mean in mathematics anyway, so I don't know what the equation is supposed to be.

Similarly, what does the comma mean?

I was using the comma to separate the 2 parts to the last which is if the first equation proved true strike out the exponent n as an index that could give a Mersenne prime.

science_man_88 · 2010-08-12, 14:11

by the way you're lucky I even got tex tags working as I didn't know the syntax until I looked it up.

science_man_88 · 2010-08-12, 14:14

...and the last equation the one we are having trouble with comes from px+c being in A002450.

CRGreathouse · 2010-08-12, 14:20

Assumptions: m, t, p, n are positive integers, p > 1.

Quote:

Originally Posted by science_man_88

$24m= 6tp+(p-7)\right m=px+c$
$24m=6tp-(p+7)\right m=px+c ?$

So we have 24m + 7 being an integer with $24m+7=p(6t\pm1)$ as appropriate.

Quote:

Originally Posted by science_man_88

$if(px+c==(4^n-1)/3,(4^\strike n -1)/3$

Quote:

Originally Posted by science_man_88

I was using the comma to separate the 2 parts to the last which is if the first equation proved true strike out the exponent n as an index that could give a Mersenne prime.

So if m is of the form (4^n-1)/3, I think you're you're saying one of these:
(a) n is not a Mersenne exponent (by which I mean that n isn't in A000043)
(b) (4n-1)/3 is not a Mersenne exponent
(c) (4^n-1)/3 is not a Mersenne exponent
(d) 2n+3 is not a Mersenne exponent

Could you clear this up?

science_man_88 · 2010-08-12, 14:24

Quote:

Originally Posted by CRGreathouse

Assumptions: m, t, p, n are positive integers, p > 1.

So we have 24m + 7 being an integer with $24m+7=p(6t\pm1)$ as appropriate.

So if m is of the form (4^n-1)/3, I think you're you're saying one of these:
(a) n is not a Mersenne exponent (by which I mean that n isn't in A000043)
(b) (4n-1)/3 is not a Mersenne exponent
(c) (4^n-1)/3 is not a Mersenne exponent
(d) 2n+3 is not a Mersenne exponent

Could you clear this up?

d is pretty much on the button if you say 2n+3 must give a prime though then that seems you leaving only what is in A121290 to start with.

science_man_88 · 2010-08-12, 14:38

now the hard part speeding it up lol. I think including the z I used for $2^z-1$ that's 7 variables to deal with.

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2010-08-12, 14:11	#304
science_man_88 "Forget I exist" Jul 2009 Dumbassville 10000011000000₂ Posts	by the way you're lucky I even got tex tags working as I didn't know the syntax until I looked it up.

2010-08-12, 14:14	#305
science_man_88 "Forget I exist" Jul 2009 Dumbassville 2⁶×131 Posts	...and the last equation the one we are having trouble with comes from px+c being in A002450.

2010-08-12, 14:38	#308
science_man_88 "Forget I exist" Jul 2009 Dumbassville 2⁶·131 Posts	now the hard part speeding it up lol. I think including the z I used for $2^z-1$ that's 7 variables to deal with.