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-   -   Leyland Primes (x^y+y^x primes) (https://www.mersenneforum.org/showthread.php?t=19347)

pxp 2020-01-10 22:58

[QUOTE=pxp;520920]I count 160 unindexed primes in my list. I'm going to be adding some more cores to the project next month, so I'm looking forward to seeing what the number will be in six months.[/QUOTE]

So it is six months later and the number of unindexed primes is still 160. Clearly I did not appreciate when I wrote the above that new prime finds beyond the intervals in which I test every Leyland number are keeping pace with unindexed terms in those intervals that subsequently acquire indices. This situation is not likely to change appreciably for another 14 months (or so) when I finally bridge to the primes with ~100000 decimal digits.

NorbSchneider 2020-01-15 00:20

Another new PRP:
17275^18246+18246^17275, 77316 digits.

NorbSchneider 2020-01-18 11:29

Another new PRP:
2618^26175+26175^2618, 89466 digits.

NorbSchneider 2020-01-24 21:29

Another new PRP:
2996^26241+26241^2996, 91228 digits.

NorbSchneider 2020-02-04 22:50

Another new PRP:
18090^18307+18307^18090, 77941 digits.

NorbSchneider 2020-02-05 22:17

Another new PRP:
18226^18359+18359^18226, 78223 digits.

NorbSchneider 2020-02-19 21:23

Another new PRP:
2816^26445+26445^2816, 91226 digits.

pxp 2020-02-20 19:21

Trivia
 
Of the currently 1671 known Leyland primes, only one has an L(x,y) where x and y are (base-10) anagrams of each other.

pxp 2020-02-22 22:04

[QUOTE=pxp;534815]That makes L(30247,300) #1470.[/QUOTE]

I have examined all Leyland numbers in the four gaps between L(30247,300) <74926>, #1470, and L(40089,82) <76723> and found 22 new primes. That makes L(40089,82) #1496.

NorbSchneider 2020-02-28 08:20

Another new PRP:
2126^26511+26511^2126, 88218 digits.

NorbSchneider 2020-03-08 22:50

Another new PRP:
19690^19941+19941^19690, 85632 digits.


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