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%I #17 Oct 02 2019 01:21:29
%S 1,2,3,5,7,26,52,75,97,98,160,227,295,413,686,901,975,1088,1481,2555,
%T 4001,4361,5637,7568,8641,19526,26633,92186
%N Numbers n such that (25*10^k + 59)/3 is prime.
%C For k>1, numbers n such that the digit 8 followed by k-2 occurrences of the digit 3 followed by the digits 53 is prime (see Example section).
%C a(29) > 2*10^5.
%H Makoto Kamada, <a href="https://stdkmd.net/nrr">Factorization of near-repdigit-related numbers</a>.
%H Makoto Kamada, <a href="https://stdkmd.net/nrr/prime/primedifficulty.txt">Search for 83w53</a>.
%e 3 is in this sequence because (25*10^3+59)/3 = 8353 is prime.
%e Initial terms and primes associated:
%e a(1) = 1, 103;
%e a(2) = 2, 853;
%e a(3) = 3, 8353;
%e a(4) = 5, 833353;
%e a(5) = 6, 83333353, etc.
%t Select[Range[0, 100000], PrimeQ[(25*10^# + 59)/3] &]
%o (PARI) is(n)=ispseudoprime((25*10^n + 59)/3) \\ _Charles R Greathouse IV_, Jun 08 2016
%Y Cf. A056654, A268448, A269303, A270339, A270613, A270831, A270890, A270929, A271269.
%K nonn,more
%O 1,2
%A _Robert Price_, May 28 2016
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