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%I #9 Apr 05 2020 10:20:56
%S 0,1,3,6,9,121,153,172,378,496,841,1594,1924,2692,4617,5148,12891,
%T 24259,24684,27690,68256,93760,104989
%N Numbers k such that (88*10^k - 1)/3 is prime.
%C Numbers such that the digits 29 followed by k occurrences of the digit 3 is prime (see Example section).
%C a(24) > 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 293w</a>.
%e 3 is in this sequence because (88*10^3 - 1)/3 = 29333 is prime.
%e Initial terms and primes associated:
%e a(1) = 0, 29;
%e a(2) = 1, 293;
%e a(3) = 3, 29333;
%e a(4) = 6, 29333333;
%e a(5) = 9, 29333333333; etc.
%t Select[Range[0, 100000], PrimeQ[(88*10^# - 1)/3] &]
%Y Cf. A056654, A268448, A269303, A270339, A270613, A270831, A270890, A270929, A271269.
%K nonn,more,hard
%O 1,3
%A _Robert Price_, Oct 11 2017
%E a(23) from _Robert Price_, Apr 05 2020
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