

A165508


Numbers k such that 10^k + 111 is prime.


1




OFFSET

1,1


COMMENTS

Terms must be congruent to 2 or 4 mod 6. Other than the first term, which produces 10^2 + 111 = 211, these terms produce primes whose decimal representation is 1 <n3 0's> 111 concatenated. These are only known to be highly probable primes for 184 and beyond. No more terms up to 15000.


LINKS



EXAMPLE

As 10111 = 10^4 + 111 is a prime, 4 is a term.


MATHEMATICA

Select[Range[5200], PrimeQ[10^# + 111] &] (* G. C. Greubel, Oct 21 2018 *)


PROG



CROSSREFS



KEYWORD

nonn,more


AUTHOR



EXTENSIONS



STATUS

approved



