Exponents with identical digits
 

Look for all prime exponents that have long strings of identical digits (all digits but one identical).

Eliminate those that have been factored or verified composite. What's left?

DoubleCheck=11111119,64,1
Test=55555553,[color=red]64[/color],0
DoubleCheck=59999999,71,1
Test=71111111,[color=red]64[/color],0

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Edit: formerly was:
Test=55555553,58,0
Test=71111111,60,0

Edited as per following post.
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M55555553 no factor to 2^64, WZ1: 154A71BC
M71111111 no factor to 2^64, WZ1: AA89D93C

see new nofactor file

I know this is an old thread, but what about patterns where the digit that's different isn't on the end of the exponent?