20070222, 22:53  #1 
"Mark"
Apr 2003
Between here and the
2·7^{2}·71 Posts 
I just discovered that 137132*5^25323+1 is composite. I assume that a couple of digits in the exponent were transposed, but haven't retested the k.
BTW, I've verified all other Sierpinki and Riesel base 5 candidates for n > 100 with Phil's phrot program. This one showed up as composite while I was testing. It also shows as composite with PFGW. 
20070223, 00:35  #2  
Dec 2006
3·11 Posts 
Quote:
You were right. Sieved that k from 20000 to 27000 for 1 minute and looked at close matches: Primality testing 137132*5^25353+1 [N1, BrillhartLehmerSelfridge] Running N1 test using base 2 Calling BrillhartLehmerSelfridge with factored part 99.97% 137132*5^25353+1 is prime! (98.3633s+0.0211s) 

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