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%I #32 Jan 25 2022 08:36:50
%S 2,4,7,14,20,22,29,31,40,80,85,224,767,952,3592,4016,4187,9239,17684,
%T 20716,30791
%N Integers k such that 10^k - 27 is prime.
%C See Kamada link - primecount.txt for terms, primesize.txt for discovery details including probable or proved primes - search on "99973".
%C The next term, if one exists, is > 100000. - _Robert Price_, Apr 25 2011
%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 = 7 is a term because 10^7 - 27 = 10000000 - 27 = 9999973, which is prime.
%Y Cf. A089675, A095714, A092767, A176987.
%K nonn,more
%O 1,1
%A Julien Peter Benney (jpbenney(AT)ftml.net), Jun 30 2005
%E a(18)-a(19) from Kamada data by _Robert Price_, Dec 10 2010
%E a(20)-a(21) from _Robert Price_, Dec 15 2010
%E Edited by _Ray Chandler_, Dec 23 2010