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Old 2015-01-18, 09:17   #6
xilman's Avatar
May 2003
Down not across

7·1,447 Posts

Originally Posted by Batalov View Post
Anyway, let's redefine XYminusYX prime as a prime p = x^y - y^x, 1 < x < y. (D.Johnson, H.Lifchitz and recently N.Schneider were collecting them for years.)
Thanks for that link.

Since the New Year I've been factoring x^y-y^x < 2^1024 where 1<x<y. There are 17289 of them, including the two special cases of 2^3-3^2 and 2^4-4^2. Right now 8948 of them remain unfactored.

Factors are still showing up at the rate of about 150 per day. Once the rate settles down a little I'll make the tables available and invite others to contribute --- some time in February I guess.

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