http://code.activestate.com/recipes/tags/primes-prime_generator/2017-04-25T11:44:27-07:00ActiveState Code Recipes2017-04-25T11:44:27-07:00Antoni Gualhttp://code.activestate.com/recipes/users/4182514/http://code.activestate.com/recipes/580789-batch-prime-generator/

<p style="color: grey"> Batch recipe 580789 by <a href="/recipes/users/4182514/">Antoni Gual</a> (<a href="/recipes/tags/primes/">primes</a>). Revision 3. </p> <p>Here is a radically differnt approach to generating primes in pure batch that overperforms everything else I have found . The idea comes from an exercise in Knuth's TAOCP Vol 3 page 617.</p>

2015-05-28T06:47:01-07:00Antoni Gualhttp://code.activestate.com/recipes/users/4182514/http://code.activestate.com/recipes/579049-prime-factors-of-an-integer-by-brent-algorithm/

<p style="color: grey"> Python recipe 579049 by <a href="/recipes/users/4182514/">Antoni Gual</a> (<a href="/recipes/tags/primes/">primes</a>, <a href="/recipes/tags/python/">python</a>). </p> <p>This recipe uses trial division to get factors below 1 milion then switches to Brent's algorithm to get bigger factors. No fast enough to break a RSA key :)</p>

2013-12-27T06:43:59-08:00Mohammad Taha Jahangirhttp://code.activestate.com/recipes/users/4188847/http://code.activestate.com/recipes/578797-public-key-encryption-rsa/

<p style="color: grey"> Python recipe 578797 by <a href="/recipes/users/4188847/">Mohammad Taha Jahangir</a> (<a href="/recipes/tags/encryption/">encryption</a>, <a href="/recipes/tags/inverse/">inverse</a>, <a href="/recipes/tags/multiplicative/">multiplicative</a>, <a href="/recipes/tags/primality_testing/">primality_testing</a>, <a href="/recipes/tags/primes/">primes</a>, <a href="/recipes/tags/publickey/">publickey</a>, <a href="/recipes/tags/rsa/">rsa</a>). Revision 3. </p> <p>Simple code to create and use public/private keypairs. Accompanied by a rudimentary encoder.</p>

2013-08-10T03:40:02-07:00Samuel 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>

2012-05-12T23:34:22-07:00Raymond Hettingerhttp://code.activestate.com/recipes/users/178123/http://code.activestate.com/recipes/577737-public-key-encryption-rsa/

<p style="color: grey"> Python recipe 577737 by <a href="/recipes/users/178123/">Raymond Hettinger</a> (<a href="/recipes/tags/encryption/">encryption</a>, <a href="/recipes/tags/inverse/">inverse</a>, <a href="/recipes/tags/multiplicative/">multiplicative</a>, <a href="/recipes/tags/primality_testing/">primality_testing</a>, <a href="/recipes/tags/primes/">primes</a>, <a href="/recipes/tags/publickey/">publickey</a>, <a href="/recipes/tags/rsa/">rsa</a>). Revision 2. </p> <p>Simple code to create and use public/private keypairs. Accompanied by a rudimentary encoder.</p>

2011-11-27T06:45:00-08:00Alexander James Wallarhttp://code.activestate.com/recipes/users/4179768/http://code.activestate.com/recipes/577964-evolutionary-algorithm-generation-of-prime-numbers/

<p style="color: grey"> Python recipe 577964 by <a href="/recipes/users/4179768/">Alexander James Wallar</a> (<a href="/recipes/tags/algorithm/">algorithm</a>, <a href="/recipes/tags/example/">example</a>, <a href="/recipes/tags/genetic/">genetic</a>, <a href="/recipes/tags/genetic_algorithm/">genetic_algorithm</a>, <a href="/recipes/tags/genetic_algorithms/">genetic_algorithms</a>, <a href="/recipes/tags/list/">list</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/primelist/">primelist</a>, <a href="/recipes/tags/primes/">primes</a>, <a href="/recipes/tags/theory/">theory</a>). </p> <p>This is an evolutionary algorithm that returns a random list of prime numbers. This code is highly inefficient for a reason. This algorithm is more of a proof of concept that if a prime was a heritable trait, it would not be a desired one. </p> <p>Parameters:</p> <p>isPrime --> n: number to check if it is prime allPrimes --> n: size of list of random primes, m: the primes in the list will be between 0 and m</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>

2010-07-27T01:57:20-07:00robert.william.hankshttp://code.activestate.com/recipes/users/4174481/http://code.activestate.com/recipes/577331-fastest-way-to-list-all-primes-below-n-in-python/

<p style="color: grey"> Python recipe 577331 by <a href="/recipes/users/4174481/">robert.william.hanks</a> (<a href="/recipes/tags/fast/">fast</a>, <a href="/recipes/tags/fastest/">fastest</a>, <a href="/recipes/tags/math/">math</a>, <a href="/recipes/tags/numbers/">numbers</a>, <a href="/recipes/tags/numpy/">numpy</a>, <a href="/recipes/tags/primes/">primes</a>, <a href="/recipes/tags/python/">python</a>). Revision 6. </p> <p>I was looking for a fast way to list all primes below n, so far i came up to this with the numpy solution the fastest. It does primes up to 10e6 in 15ms in my old machine, and it is capable of reaching 10e9. </p>

2010-07-20T04:05:00-07:00Alejandro Peraltahttp://code.activestate.com/recipes/users/4174433/http://code.activestate.com/recipes/577318-infinite-list-of-primes-yay/

<p style="color: grey"> Python recipe 577318 by <a href="/recipes/users/4174433/">Alejandro Peralta</a> (<a href="/recipes/tags/iterators/">iterators</a>, <a href="/recipes/tags/numbers/">numbers</a>, <a href="/recipes/tags/primes/">primes</a>). </p> <p>It's an iterator that returns prime numbers. </p> <p>Got the idea from here: <a href="http://www.cs.hmc.edu/%7Eoneill/papers/Sieve-JFP.pdf" rel="nofollow">www.cs.hmc.edu/~oneill/papers/Sieve-JFP.pdf</a></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>

2009-11-04T06:52:06-08:00Maxime Fontenierhttp://code.activestate.com/recipes/users/4172150/http://code.activestate.com/recipes/576948-simple-primes-generator/

<p style="color: grey"> Python recipe 576948 by <a href="/recipes/users/4172150/">Maxime Fontenier</a> (<a href="/recipes/tags/any/">any</a>, <a href="/recipes/tags/generator/">generator</a>, <a href="/recipes/tags/numbers/">numbers</a>, <a href="/recipes/tags/primes/">primes</a>). </p> <p>Simple prime generator. </p> <p>I write it as a sample usage of the any function.</p>

2008-12-27T11:45:09-08:00Louis RIVIEREhttp://code.activestate.com/recipes/users/4035877/http://code.activestate.com/recipes/576596-sieve-of-eratosthenes/

<p style="color: grey"> Python recipe 576596 by <a href="/recipes/users/4035877/">Louis RIVIERE</a> (<a href="/recipes/tags/algorithms/">algorithms</a>, <a href="/recipes/tags/eratosthenes/">eratosthenes</a>, <a href="/recipes/tags/math/">math</a>, <a href="/recipes/tags/primes/">primes</a>). Revision 3. </p> <p>Returns primes &lt; n.</p>

2008-07-26T19:45:12-07:00Phil Huffmanhttp://code.activestate.com/recipes/users/4165783/http://code.activestate.com/recipes/576380-prime-look-up-program/

<p style="color: grey"> Python recipe 576380 by <a href="/recipes/users/4165783/">Phil Huffman</a> (<a href="/recipes/tags/algorithm/">algorithm</a>, <a href="/recipes/tags/primes/">primes</a>). </p> <p>Finds the nth prime without using a sieve algorithm. </p>