http://code.activestate.com/recipes/tags/prime-algorithm/2013-08-10T03:40:02-07:00ActiveState Code Recipes2013-08-10T03:40:02-07:00Samuel James Ericksonhttp://code.activestate.com/recipes/users/4187478/http://code.activestate.com/recipes/578632-de-polignacs-formula/

<p style="color: grey"> Python recipe 578632 by <a href="/recipes/users/4187478/">Samuel James Erickson</a> (<a href="/recipes/tags/factorial/">factorial</a>, <a href="/recipes/tags/n/">n</a>, <a href="/recipes/tags/prime/">prime</a>, <a href="/recipes/tags/primes/">primes</a>). Revision 4. </p> <p>Obtains the total number of factors of p in n! for any prime p.</p>

2011-11-05T23:42:37-07:00Alexander James Wallarhttp://code.activestate.com/recipes/users/4179768/http://code.activestate.com/recipes/577935-primelist/

<p style="color: grey"> Python recipe 577935 by <a href="/recipes/users/4179768/">Alexander James Wallar</a> (<a href="/recipes/tags/list/">list</a>, <a href="/recipes/tags/numbers/">numbers</a>, <a href="/recipes/tags/prime/">prime</a>, <a href="/recipes/tags/primelist/">primelist</a>, <a href="/recipes/tags/primes/">primes</a>, <a href="/recipes/tags/theory/">theory</a>). Revision 3. </p> <p>This module returns all the prime numbers strictly less than n. For this code to print out all of the primes n inclusive, in the range, n+1 must be substituted for n.</p>

2010-08-06T11:20:34-07:00Thomas Lehmannhttp://code.activestate.com/recipes/users/4174477/http://code.activestate.com/recipes/577329-some-prime-generation-algorithms/

<p style="color: grey"> Python recipe 577329 by <a href="/recipes/users/4174477/">Thomas Lehmann</a> (<a href="/recipes/tags/generation/">generation</a>, <a href="/recipes/tags/is_prime/">is_prime</a>, <a href="/recipes/tags/prime/">prime</a>, <a href="/recipes/tags/primes/">primes</a>). Revision 4. </p> <p>Basic idea was to see the difference between different prime algorithms in time. Also they are not perfect the output shows that really higher numbers let grow the difference why I have separated this into functions to make it visible. I add this here because I have been missing this very often when I have been searching for algorithms.</p> <ul> <li>The 'is_prime' is a well known way of checkin for a number being prime or not.</li> <li>The sieve of Erastothenes is simply to strike out multiples of a given value; the primes will remain.</li> <li>the function 'profile' is a decorator for functions measuring the execution time</li> <li>Some information are in the comments of the code</li> </ul>

2010-05-19T17:02:28-07:00AJ. Mayorgahttp://code.activestate.com/recipes/users/4173476/http://code.activestate.com/recipes/577229-prime-perfect-and-fibonacci-number-widget-class/

<p style="color: grey"> Python recipe 577229 by <a href="/recipes/users/4173476/">AJ. Mayorga</a> (<a href="/recipes/tags/cryptography/">cryptography</a>, <a href="/recipes/tags/numbers/">numbers</a>, <a href="/recipes/tags/prime/">prime</a>, <a href="/recipes/tags/primes/">primes</a>). Revision 2. </p> <p>A class Ive had in my snippets for awhile that can generate prime, perfect and fibonacci sequences as well as check whether or not a supplied value is any of them.</p>

2009-11-13T09:47:53-08:00Adam M Prosthttp://code.activestate.com/recipes/users/4172124/http://code.activestate.com/recipes/576956-primes-from-1-to-100/

<p style="color: grey"> Python recipe 576956 by <a href="/recipes/users/4172124/">Adam M Prost</a> (<a href="/recipes/tags/prime/">prime</a>). Revision 2. </p> <p>Get the primes from 1 to 100 or really any range you choose.</p>

2013-01-31T23:41:21-08:00Justin Shawhttp://code.activestate.com/recipes/users/1523109/http://code.activestate.com/recipes/576737-inverse-modulo-p/

<p style="color: grey"> Python recipe 576737 by <a href="/recipes/users/1523109/">Justin Shaw</a> (<a href="/recipes/tags/mod/">mod</a>, <a href="/recipes/tags/modulo/">modulo</a>, <a href="/recipes/tags/number/">number</a>, <a href="/recipes/tags/prime/">prime</a>, <a href="/recipes/tags/theory/">theory</a>). Revision 4. </p> <p>Very rarely it is necessary to find the multiplicative inverse of a number in the ring of integers modulo p. Thie recipe handles those rare cases. That is, given x, an integer, and p the modulus, we seek a integer x^-1 such that x * x^-1 = 1 mod p. For example 38 is the inverse of 8 modulo 101 since 38 * 8 = 304 = 1 mod 101. The inverse only exists when a and p are relatively prime.</p>

2009-02-03T15:47:06-08:00dthhttp://code.activestate.com/recipes/users/4169078/http://code.activestate.com/recipes/576640-prime-number-generator/

<p style="color: grey"> Python recipe 576640 by <a href="/recipes/users/4169078/">dth</a> (<a href="/recipes/tags/eratosthene/">eratosthene</a>, <a href="/recipes/tags/generator/">generator</a>, <a href="/recipes/tags/number/">number</a>, <a href="/recipes/tags/of/">of</a>, <a href="/recipes/tags/prime/">prime</a>, <a href="/recipes/tags/sieve/">sieve</a>). Revision 7. </p> <p>Generate all prime numbers up to n.</p>