20180806, 21:26  #243 
Sep 2010
Weston, Ontario
2×7×13 Posts 
My estimate is about 1 in 100. So about 30 Leyland primes with digitsize ranging from 400000 to 403000. Seems like a lot.

20180806, 21:39  #244 
Sep 2010
Weston, Ontario
266_{8} Posts 
Norbert Schneider recently PRP'd L(47012,297). At 116250 decimal digits, this is now the 6th largestknown Leyland prime. Moreover, this gives Norbert five of the top ten. Congratulations!

20190327, 19:44  #245 
"Norbert"
Jul 2014
Budapest
2·7^{2} Posts 
I search in the interval 13,000<=x<=15,000, for new PRPs
and also doublecheck the known PRPs. Currenttly I reached x=13,800, so far no new PRPs and the known PRPs are confirmed. Hans, what is your next range after the 100,000 digits is finished? 
20190419, 21:03  #246  
Sep 2010
Weston, Ontario
2×7×13 Posts 
The long compute
Quote:
Beginning on 26 June 2017, I am today done with my search of Leyland numbers between L(40210,287) <98832> and L(40945,328) <103013>. I found 67 new primes. The (x,y) values of the 25046458 Leyland numbers in the gap were precomputed, sorted by size, and packaged into bundles of 88670. Each bundle was assigned to an available core on one of my Macs. The computations were done in Mathematica (versions 8 or 9) where each Leyland number was checked for GCD(x,y)==1 before applying PrimeQ. A given bundle would take from four to six weeks to check. There's no point in listing the new primes. Refer to my Leyland prime indexing effort which is always uptodate. Norbert asked what I'm doing next. I'm back to extending the prime indices which have languished at L(17691,1508) <56230>, #1179, for these almosttwo years. I've already started. 

20190419, 21:53  #247  
"Mark"
Apr 2003
Between here and the
5·1,201 Posts 
Quote:


20190420, 00:08  #248 
Sep 2010
Weston, Ontario
10110110_{2} Posts 
Yes. PrimeQ is Mathematica's PRP test.

20190420, 00:36  #249  
"Rashid Naimi"
Oct 2015
Remote to Here/There
7·277 Posts 
I looked this up. Others might find it useful. The subject has come up more than once in the past.
Quote:


20190420, 00:36  #250 
Sep 2010
Weston, Ontario
2·7·13 Posts 

20190502, 14:15  #251 
Sep 2010
Weston, Ontario
2×7×13 Posts 

20190512, 13:47  #252 
Sep 2010
Weston, Ontario
2×7×13 Posts 

20190605, 07:01  #253 
Sep 2010
Weston, Ontario
2×7×13 Posts 

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