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Iterations Completed Digit Count



02/08/16 I have not made any updates to this site in many years, but I still occassionally get interesting comments from readers. I received an email that wished to remain anonymous, with the text of the email reading as follows: Here are some thoughts on "search for and classification of Lychrel numbers". We (small group) investigated lychrel numbers as voluntary research project in our school (in Germany), and these are some of the results. .pdf = document, .tex = source, .hs = search program (Haskell)

The work is interesting and original and I decided that it should be shared with a larger audience than my own inbox. A job well done to the team!

The file that can be found here: lychrel842.zip

12/27/11 I have been seriously remiss in delaying the announcment of 1 billion iterations of the 196 problem. Romain Dolbeau sent me the following file header: the "Sun Oct 2 16:20:43 UTC 2011 : 413930770 ; 1000000000 -> 3932472453326071578739224"!!

A billion iterations!!! It's been a long time on this road, and when I started out all this craziness so long ago, none of us even imagined we'd ever get so far. WOW. Congratulations to Romain!!

I have almost completely thrown in the towel on the project. Romain has made such huge advances in the ability to calculate the iterations, that I was never going to be able to keep anything productive going on while I was always just chasing him at a tiny fraction of the speed. So I have wandered off the topic, and even with huge news such as this, I just couldn't ever seem to "find the time" to update the site. (Which really just means I have finally run out of interest in the project.) It took a number of things happening right here around December where I had to make some updates and get some additional news out.

Romain has rolled out a page here: http://www.caps-entreprise.com/private/dolbeau/p196/p196.html to access the source for his app and any notes he may feel like adding. With any luck, it'll stay up a while. I'll try to mirror it locally, but you know how that goes over the years...

Matt Stenson has been as busy as ever running that old Lychrel Seeds search. Matt has dedicated a lot of years to the search to determine how many Lychrel seeds there are and now, he has answered the question for all 18 digit numbers as well. Have a look at the Lychrel Seeds page to marvel in Matt's glory and let him know what an amazing effort he has completed. Like me, Matt has kind of decided that he's not going to carry the search out for Lychrel seeds any further than he has. And who can blame him? He's spent at least 6 years letting that program run. Even compared to John Walker's original "Three Years of Comupting", Matt has gone above and beyond. Thanks for all you've done Matt! Hope you've enjoyed it as much as I have!

I would like to introduce Jake Harry. Jake forgot to tell me where he's from, but he has devised a new method of generating a palindrome from a number, that is similar to the reverse and add process, yet is a different process. I have copied Jake's instructions to a new page that can be located here. It is an interesting new look at a problem some of us have probably grown stale with. He is using it as a method to generate palindromes that even solves 196 and the other Lychrel Seeds. It's good to see some fresh eyes looking at the problem and coming up with new ideas. Thanks for the comments Jake and the interesting paper!

Back in October, Matthew Cowen-Green in the United States sent me a Java application that tests for convergence between two lychrel threads. Matthew took it upon himself to write the app after reading it on my Wish List. It took me forever to get around to playing with it, but I finally did and it seems to work quite well. I have put a copy HERE, if you want to play around with it.

9/25/11 I'd like to introduce Romain Dolbeau of France. Romain has created another amazing parallel processing app and is lucky enough to have access to an incredibly fast network of machines.

Let me put that in perspective when I say and incredible network of machines...

As mentioned below, I have been re-running the data sets for verification. Back in Oct 2010, I started at the 210 mark and this week, I got over 280. So 70 million digits in about a year.

Romain started for the first time, from 0 in August of 2011 and by utilizing only free time on the system, has completed everything up to 375 millions digits!! Where I am taking a little over 4 days to do a dataset right now, Romain's system is doing it in a little UNDER 2 hours! He sent me verification data for various points as he continued beyond 234, which is what is posted here online, and 300 which I haven't shared. His numbers and iterations matched exactly everything I had. His app is working properly and the speed is simply jaw dropping. I had to cringe every time I got a new email from him asking to verify a new point, just to wonder how far he'd moved in a day or two. I very quickly realized he was going to completely eclipse everything that has been done to this point.

I have updated the Verification Page and the Milestones Page with the information Romain has sent to me.

I had to be honest with him that it was sad for me, for him to take away my records so effortlessly, but he's a great guy to talk with and is rapidly moving in on the 1 billion iteration mark. He has given permission for me to release the source to his code, so if anyone wants to poke around inside his code, let me know and I'll send it along. He acknowledges that a lot of "detail work" needs to be cleaned up, but it is an awesome piece of work as it is, and I should have gotten credit out to him weeks ago for his achievements.

Thanks again to Romain for all his support and the effort he put into this. It's truly great work!! I'm very happy he has shared it with us all!

Now if I could only spend $30,000 to buy a high speed cluster like he's using, I could have my records back! :-)

1/25/11 Like so many things online, Ben Despres' website disappeared off the web a couple years ago. Copies of it were held in the Internet Archive Wayback Machine and I have blatently copied all of Ben's work to a local mirror to maintain the historical value of the page.

I don't honestly think that Ben would mind, and if he asks me to remove it from this site I will, but I think the value of what he was doing is worth the time to mirror it here.

Now if I could only get a copy of Istvan's page as well... But it seems to be lost to the ages of digital darkness. Sigh...

I have completed the verification of all data sets up to 240 million digits.

1/13/11 It is difficult to rebuild the site in a foreign language in which I'm reasonably comfortable like Spanish. Simply verifying the links and trying to maintain the formatting is a huge task. But then I started and completed German, and that was a little more difficult. The difference being, that I don't recognize even 1/2 of one percent of the words. Nor can I relate to the syntax of the sentances, so I have very little idea if I am breaking the sentances correctly.

Now, I've discovered just how blind you can be and what it must feel like to be completely illiterate at all, by trying to translate the site into Hindi! Now, I can't even recognize the letters of the page, and have to rely 100% on Google to do an accurate translation and not mess up my meaning. It is probably a completely lost cause, but if it gets even one more student to see the site, and appreciate the beauty of the problem, than it is worth it. And if you are reading this in any of the languages that I have tried to translate to, and you want to take on the task of truely localizing the pages for your language, I would be happy for your help. (And credit you on the pages of course!)

1/12/11 Continuing what I started a couple days ago, I have completed translating the site into German as well. If you're reading the site in one of the languages other than English, and you notice something that is just completely messed up, please let me know and I'll do my best to fix it. Thanks.

01/09/11 For no reason other than I thought it would be fun to do, I've been translating the site into languages other than English. Well, actually Google Translate has been doing all of the heavy work, but the program murders HTML code, so it's been time consuming to get all the links, paragraphs, and other tags corrected to the new pages and get everything looking right again.

Google does a reasonable job I think of getting the vast majority of the translation correct. If you are reading this in a language other than English, and it just doesn't make any sense, then I apologize. But I think the software does a good enough job, that most of the important points should come across.

I started with Spanish and Italian and I hope to get around to other languages as I can.

In addition, I have continued verifiying the milestone files as described below. I am currently working on the 240 data set. It's a slow process, just like it was the first time around.

11/06/10 If you've been to the site before, you'll recognize a major transformation since the last time you were here. For days I have been altering the layout and look of the site. Trying new things and just generally playing around. I'll continue to repair broken links, and make edits that needed to be made years ago. I find myself with a renewed interest in the topic, and the site in general. We'll see if it goes anywhere new.

If you find a broken link, if you want to let me know about it, it'll help me get it corrected. If you don't want to take the time to let me know about it, I understand, and will get to it eventually as I find it.

10/25/10 I have made a number of updates to the site in general to correct links that have broken over the years of inactivity. I have been running Pierre Andre Laurent's application on a new machine recently, and may continue to do so, to increase the quest to new levels.

At the moment, I am backing up a bit, and verifying some of the files that I had previously. I never reran anything beyond 210 million, so I started there again a few weeks ago, and have been checking the milestones against the verification page, and my files. I figure since finishing this group, will mean I have run the entire quest twice over the years, but with different machines and different applications than the first go around, the files have a far greater reliability.

I'll probably keep you posted...

If you're looking for older news, try the archives from the "MY BLACKBOARD" pulldown menu.