PARI's commands

[science_man_88]

got it working:

test(n)=for(sqrN=sqrtint(n),n,sqrN2=sqrN^2;PCS=sqrtint(abs(sqrN2 - n));if(Mod(n,PCS+sqrN)!=0,,print(sqrN+PCS"*"sqrN-PCS);break()));

[3.14159]

Originally Posted by science_man_88

got it working:

test(n)=for(sqrN=sqrtint(n),n,sqrN2=sqrN^2;PCS=sqrtint(abs(sqrN2 - n));if(Mod(n,PCS+sqrN)!=0,,print(sqrN+PCS"*"sqrN-PCS);break()));

It works, but trial division outspeeds it by a factor of 40.

Nevermind.. It gains the edge when it comes to a c18.

[science_man_88]

Originally Posted by 3.14159

It works, but trial division outspeeds it by a factor of 40.

I knew these guys were lying kooks.

Yeah the largest Mersenne prime I felt like letting it finish was 2^19-1, anything over that I stopped at about 15 seconds in.

[3.14159]

Also; For the rest of you out there;

I thought of this type of prime; k * (n! * p(n)#) + 1, or, if you'd like to generalize further, + b, where b is an integer.

There should be a k such that k * (n! * p(n)#) + 1 is composite with every n > 1.

I'll try looking for some that fit that description, to some extent.

[science_man_88]

Originally Posted by 3.14159

Also; For the rest of you out there;

I thought of this type of prime; k * (n! * p(n)#) + 1, or, if you'd like to generalize further, + b, where b is an integer.

There should be a k such that k * (n! * p(n)#) + 1 is composite with every n > 1.

I'll try looking for some that fit that description, to some extent.

p(n)# means what again ? I forgot.

[3.14159]

Originally Posted by science_man_88

p(n)# means what again ? I forgot.

p(n)#.

p(5)# = 2 * 3 * 5 * 7 * 11 = 2310.

Of course, the smallest prime of the type I mentioned is 3.

[science_man_88]

Originally Posted by 3.14159

p(n)#.

p(5)# = 2 * 3 * 5 * 7 * 11 = 2310.

so a primorial up to prime(n).

[3.14159]

Originally Posted by science_man_88

so a primorial up to prime(n).

Yes. Product of the first n primes.

And; Patch this for me.

cs(a,x,m)=for(n=a,x,print(m*fp(n)+1));if(isprime(m*fp(n)+1),break)

Note that fp(n) = n! * p(n)#.

I got an error message;

***   gtos expected an integer, got 'n'.

[science_man_88]

Originally Posted by 3.14159

Yes. Product of the first n primes.

And; Patch this for me.

cs(a,x,m)=for(n=a,x,print(m*fp(n)+1));if(isprime(m*fp(n)+1),break)

Note that fp(n) = n! * p(n)#.

I got an error message;

***   gtos expected an integer, got 'n'.

only thing I see wrong is p(n)# lol

never mind I fixed it embed the if and it worked for me lol.

[3.14159]

Originally Posted by science_man_88

only thing I see wrong is p(n)# lol

never mind I fixed it embed the if and it worked for me lol.

.. Wait.. What revisions did you make to the code?

Also; Prime: 590 * (400! * p(400)#) + 1.

[science_man_88]

Originally Posted by 3.14159

.. Wait.. What revisions did you make to the code?

Also; Prime: 590 * (400! * p(400)#) + 1.

cs(a,x,m)=for(n=a,x,print(m*fp(n)+1);if(isprime(m*fp(n)+1),break(1)))