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Recent Activity on SelectedPapers.net

Deen Abiola replied RE: A Hidden Signal in the Ulam sequence (14 hours ago)
Oh cool, how appropriate that of the motivations behind this was studying cellular automatons and complexity.
Andrzej Solecki replied RE: A Hidden Signal in the Ulam sequence (1 day ago)
+Richard Green Oh, so you know Jan? And perhaps Sioma as well?

Small world...
Rachel Blum (Groby) replied RE: A Hidden Signal in the Ulam sequence (1 day ago)
Finally having read the paper, section 2.4 specifically points out Ulam-type sequences are exhibit periodic or chaotic behavior. (No useful insight per se, just wanted to wrap up that dangling thread)

And I'm glad they already have answered my implicit question "what about signals in other Ulam-sequences", because that means I can go back to actually doing my actual work instead of futzing around myself :)
Richard Green replied RE: A Hidden Signal in the Ulam sequence (1 day ago)
+Piotr Blass and I already know each other, via Jan Mycielski. We met in Boulder in 2009.
Piotr Blass replied RE: A Hidden Signal in the Ulam sequence (1 day ago)
We shall investigate this sequence numerically
Thanks Bob Calder from cool Poland

Sent from my iPhone
Timothy Gowers replied RE: A Hidden Signal in the Ulam sequence (1 day ago)
+Víktor Bautista i Roca The video you link to is an animation of the Ulam spiral, which is not the same as the Ulam sequence. For a visual representation of the sequence, try this plot of a large initial segment of it (which I found by following a link from OEIS): https://oeis.org/A002858/a002858.png
Bob Calder replied RE: A Hidden Signal in the Ulam sequence (1 day ago)
+Richard Green refer questions on Ulam to +Piotr Blass, first editor of the Ulam Quarterly.
Andrzej Solecki replied RE: A Hidden Signal in the Ulam sequence (1 day ago)
+Debashish Samaddar - if you understand that checking  things from the past is difficult in Wikipedia as it did not exist then, you might have read two chapters on Ulam in Indiscrete Thoughts by Gian-Carlo Rota (pp.60-85) as he knew much more on Los Alamos than Sakharov. And do you really see debunking a nasty gossip as a sign of rudeness?
Juho-Petteri Yliuntinen replied RE: A Hidden Signal in the Ulam sequence (1 day ago)
Refreshingly interesting reading, the post and the comments discussion. The description "The whole thing is empirical and mysterious" made my day roughly 25,71% better, thanks +Richard Green​!
Richard Green replied RE: A Hidden Signal in the Ulam sequence (1 day ago)
+John Cook, thanks for tweeting a link to this post!
Hamilton Carter replied RE: A Hidden Signal in the Ulam sequence (1 day ago)
Thanks +Richard Green, I'll get on it.
Richard Green replied RE: A Hidden Signal in the Ulam sequence (1 day ago)
+Hamilton Carter, you should read the paper. The whole thing is empirical and mysterious.
Hamilton Carter replied RE: A Hidden Signal in the Ulam sequence (1 day ago)
Hi +Richard Green, is there a brief explanation of how 2.571 was obtained, or should I go read the paper?
Timothy Gowers replied RE: A Hidden Signal in the Ulam sequence (1 day ago)
+Richard Green it is indeed close enough to my area of expertise that I'm wondering whether it would be worth having a go at. Maybe a nice holiday project.
Debashish Samaddar replied RE: A Hidden Signal in the Ulam sequence (1 day ago)
+Andrzej Solecki yes it is hard to check because I read it as a probable explanation of Sakharov's unexplained "Third Idea" in a magazine published in another language in another country, then aligned with USSR before Wikipedia came into existence. Before the WWW and the "Internet" (as a merged network from various places) itself came into being. Wikipedia itself isn't so reliable anyway. Do you remember such a time? Besides, why are you so rude?
Andrzej Solecki replied RE: A Hidden Signal in the Ulam sequence (1 day ago)
+Debashish Samaddar  - is it really so hard to check the 'knowledge' retained  in the head and obtained from God-knows-what sources?  The first step might be a place called Wikipedia, you might have heard of it.

Were Stanislaw Ulam alive, you might have earned an invitation to appear in court for publicly writing such a piece of nonsense.
Richard Green replied RE: A Hidden Signal in the Ulam sequence (1 day ago)
Thanks, +Víktor Bautista i Roca! I will watch later when I have a good net connection.
Richard Green replied RE: A Hidden Signal in the Ulam sequence (1 day ago)
+Timothy Gowers, I was very interested to hear your reaction, because this sounds like a problem close to your area of expertise. The author was also motivated by the existence of (infinitely many) 3-arithmetic progressions in the sequence, which he says would follow if the sequence had positive density, by using a result of Roth.