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Integers k such that 10^k - 87 is prime.
2

%I #25 Jul 27 2021 05:02:55

%S 2,1800,2368,15328

%N Integers k such that 10^k - 87 is prime.

%C See Kamada link - primecount.txt for terms, primesize.txt for discovery details including probable or proved primes - search on "99913".

%C a(5) > 10^5. - _Tyler NeSmith_, Jul 26 2021

%H Makoto Kamada, <a href="https://stdkmd.net/nrr/prime/">List of near-repdigit-related prime numbers</a>.

%H <a href="/index/Pri#Pri_rep">Index entries for primes involving repunits</a>.

%e k = 2 is a term because 10^2 - 87 = 100 - 87 = 13, which is prime.

%Y Cf. A089675, A095714, A092767.

%K more,nonn

%O 1,1

%A Julien Peter Benney (jpbenney(AT)ftml.net), Jun 30 2005

%E a(4) from Kamada data by _Robert Price_, Dec 13 2010

%E Edited by _Ray Chandler_, Dec 23 2010