[seqfan] Re: The Jacob's Ladder sequence: nice but not new

Hans Havermann gladhobo at bell.net
Thu Feb 22 23:47:01 CET 2018

> Alberto Fraile, Roberto Martínez, and Daniel Fernández, Jacob's Ladder:
> Prime numbers in 2d, arXiv preprint arXiv:1801.01540, 2017

I finally had a chance to go through this. One of the sillier things (I thought) was the assertion of "a possible trend in the terms ending in 1, 3, 5, 7 and 9, being the number of them 459, 479, 484, 487 and 506 respectively in the first 2415 zeroes, i.e. showing a clear linear increase". All that I see is that the counts are roughly the same. For A064940, the digits would be 0, 2, 4, 6, and 8. I did final-digit cumulative counts all the way up to 11631 and color-coded the digit-endings: (0, red), (2, magenta), (4, black), (6, green), and (8, blue). I've put the graph here:


So they are saying that at 2415 the colors are arranged lowest-to-highest: red, magenta, black, green, and blue. But observe how the plots evolve. There's nothing here but chance.

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