Top of page Bottom of page
Home Windows 10 Windows 7 Sydney PC&TUG Web Design Primes Factors Factor Records Nice Split Digital Photos Links Downloads Archives Contact Us


Search this site only
• Recent Factors

Nov 1, 2018
682 • 10227 - 7  [757227]c228 8026761139­4435662998­8708262644­8592864380­1303605914­9540951487­4327<p64>
Oct 27, 2018
67 • 10228 + 23  [742277]c223 7140458117­4690826427­7030427859­3404199503­0112017592­1229647664­6447545348­3432167462­39<p82>
Oct 25, 2018
71 • 10227 - 53  [782263]c223 1651480977­1424199518­7714779313­3777690188­5566701321­3931824879­8908082589­3967863<p77>
Oct 21, 2018
8 • 10228 + 3  [802273]c224 3378703940­1374386597­8931344578­9562826676­3764511850­5837833<p57>
Oct 18, 2018
43 • 10228 + 11  [472279]c224 4258679474­9605523879­7273008386­7867662683­5731744964­7321672176­8869560040­8623723577­17<p82>

• Other Topics

Here is a mirror of this web-site, but in a parallel universe using black text on a pale background.

Using exponents up to 100,000, primes of the form k • 2n ± 1 were calculated using the latest version of the free OPENpfgw program available from SourceForge.

More photos have been added. See our friend Bill G and a "floating ship" which appears to hang suspended above the horizon.

See some screen-shots of Windows 7. 

See screen-shots of various Insider Builds of Windows 10. 

See interesting shapes created just using CSS code.

See my personal Blog: bobb777 and the Blog of the Sydney PC User Group: sydneypcug.

The latest addition is an Unscramble program to solve Jumble™ puzzles.

The Sydney PC User Group is an independent club of users discussing all aspects of personal computers.

The members also help each other solve computer problems.  It has several Special Interest Groups or SIGs including Genealogy, Digital Photography and Web Design.

This web-page was initially written with NetObjects Fusion, one of the programs used by the Web Design SIG.  See the Reports for recent meeting information.

More recently I've written some Perl scripts to construct web-pages based on tables of integer factors that I have discovered.

Use the inbuilt DOS ftp command to upload files quickly from a batch file.  If uploading different files each time, however, use a Windows FTP program like the free Core-FTP program instead.

Read the details in this short tutorial.

See what soft hyphens are all about.  Enable Javascript and check out your browser by loading this test page.  We check the Windows version of Apple's Safari browser.

Unicodes may be necessary in HTML when named symbols are not available (for Cyrillic characters Я and и for example).

Check that you have valid HTML or XHTML code online using the World Wide Web Consortium (W3C) official site or offline using the free  CSE HTML Validator Lite program.

A 116-digit personal record prime factor has been found on Wed Feb 15th, 2017.  It divides the 233-digit number 5 • 2790 + 1 = p116 • p117.

A 112-digit personal record prime factor has been found on Fri April 1st, 2016.  It divides the 226-digit number 7 • 2746 + 1 = p112 • p114.

Work is progressing on factorising numbers of the form k • 2n ± 1 with k (odd) from 3 to 15 and n ≤ 1000.  The results are recorded by Mikael Klasson.

Msieve, written by Jason Papadopoulos is described.  It contains fast code to solve large sets of linear equations.  See the new Perl script to automate Msieve post-processing after a GGNFS run.

The year 2015 sees the culmination of a four and a half-year project to factor seventeen very large Cunningham numbers.

A technique was used where the sieving data was re-used by the authors Thorsten Kleinjung, Joppe W. Bos, and Arjen K. Lenstra, described in their paper, published on January 12, 2015.

Updated: Fri Nov 2, 2018
© 2018 Bob Backstrom
Home Windows 10 Windows 7 Sydney PC&TUG Web Design Primes Factors Factor Records Nice Split Digital Photos Links Downloads Archives Contact Us