%I #20 Jan 17 2019 13:44:08
%S 2,3,11,15,23,29,44,71,83,95,159,383,404,548,633,6409,8793,24146,
%T 25727,64436,74335,76875
%N Numbers n such that 10^n - 53 is prime.
%C The next term, if it exists, is > 100000.
%C See Kamada link - primecount.txt for terms, primesize.txt for discovery details including probable or proved primes - search on "99947".
%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 10^3 - 53 = 947 which is a prime number.
%t m=1000; For[n=1, n<m, If[PrimeQ[10^n-53], Print[n]]; n++ ]
%o (PARI) is(n)=ispseudoprime(10^n-53) \\ _Charles R Greathouse IV_, Jun 13 2017
%Y Cf. A108330, A108328.
%K more,nonn
%O 1,1
%A _Robert Price_, Dec 21 2010
%E Corrected terms a(17) and a(18) by _Robert Price_, Dec 24 2010
%E a(20-22)=64436,74335,76875 from _Robert Price_, May 29 2011
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