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%I #15 Jun 09 2024 22:02:17
%S 0,2,3,5,6,14,15,38,60,66,95,101,206,225,1382,1782,2046,2220,2484,
%T 2592,4578,11238,13016,18329,148982,196070
%N Numbers k such that 6*10^k + 73 is prime.
%C For k > 1, numbers k such that the digit 6 followed by k-2 occurrences of the digit 0 followed by the digits 73 is prime (see Example section).
%C a(27) > 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/prime_difficulty.txt">Search for 60w73</a>.
%e 3 is in this sequence because 6*10^3 + 73 = 6073 is prime.
%e Initial terms and associated primes:
%e a(1) = 0, 79;
%e a(2) = 2, 673;
%e a(3) = 3, 6073;
%e a(4) = 5, 600073;
%e a(5) = 6, 6000073; etc.
%t Select[Range[0, 100000], PrimeQ[6*10^# + 73] &]
%Y Cf. A056654, A268448, A269303, A270339, A270613, A270831, A270890, A270929, A271269.
%K nonn,more,hard
%O 1,2
%A _Robert Price_, Apr 29 2017
%E a(25)-a(26) from _Robert Price_, Apr 04 2019
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