Constructing a sieve for trial factors

[lavalamp]

Ah yes, good point.

[davieddy]

Originally Posted by davieddy

The kth bit represents 2kp+1.
I want to eliminate all multiples of a prime x (x<2p).
For what k (<x) is 2kp+1 a multiple of x?
Is there a clever way of answering(/programming) this?

David

THX to all contributors (except Silverman who merely
suggested I went back to some sort of skool).
I Googled "Extended Euclid algorithm" (THX axn1) and
I would guess this was what mfh was trying to say.
I thought to myself (while solving this problem) surely
division in modular arithmetic can't be as silly as this.

Back to the sieve:
I simply went through 1<=k<x as Lavalamp suggested
to find the first k.(It proved not time critical).
I selected 15015 bytes as a reasonable length of sieve
to repeat over.
I assumed (proved?) that each multiple of x repeated
each time k increased by x.

(The appliance of science)

THX all, David

[R.D. Silverman]

Originally Posted by davieddy

THX to all contributors (except Siverrman who merely
suggested I went back to some sort of skool).

You don't have to go back to school.

You DO have to get some books on elementary number theory
and READ them.

If you are not willing to do even the most basic learning that
is required to dabble in number theory, then why should anyone
else help you?

IMO, people in this newsgroup who show that they want to be
WILLFULLY ignorant should be banned by the moderators.

And your attitude SUCKS. You want everything handed to you.

[xilman]

Originally Posted by R.D. Silverman

If you are not willing to do even the most basic learning that is required to dabble in number theory, then why should anyone
else help you?

Because they enjoy being helpful perhaps?

Paul

[R.D. Silverman]

Originally Posted by xilman

Because they enjoy being helpful perhaps?

Paul

We should want to help those who are *** willing to learn ***.
We should not be doing other people's homework for them.

[davieddy]

MFGoode where are you now?

[davieddy]

Originally Posted by xilman

Because they enjoy being helpful perhaps?

Paul

Altruism has its advantages.

[davieddy]

Originally Posted by R.D. Silverman

We should want to help those who are *** willing to learn ***.
We should not be doing other people's homework for them.

I thought of posting it in the homesork thread,
but was scared I might be recognized

David

[lavalamp]

Originally Posted by R.D. Silverman

We should want to help those who are *** willing to learn ***.

People who aren't willing to learn don't ask questions.

davieddy had a gap in his knowledge that he wished to fill so he asked a question. That's when you came along, made light of his issue and questioned his education.

Incidentally, there was only one time that modular arithmetic was even mentioned in school for me, and that was when everyone (including the teacher) got bored of statistics and so we did half a lesson on encryption.

[davieddy]

Originally Posted by lavalamp

People who aren't willing to learn don't ask questions.

davieddy had a gap in his knowledge that he wished to fill so he asked a question. That's when you came along, made light of his issue and questioned his education.

"They" didn't make light of my "issue" at all.
I did have a gap in my knowledge, asked the question which
pinpointed it, and received several useful replies.

[davieddy]

Originally Posted by lavalamp

Incidentally, there was only one time that modular arithmetic was even mentioned in school for me, and that was when everyone (including the teacher) got bored of statistics and so we did half a lesson on encryption.

I never learned any modular arithmetic at my skool either.
Statistics neither. OTOH both are interesting. I implemented
some RSA a couple of years ago, just to prove I understood
what it was about.

David