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Prime numbers after which at least four distinct classes modulo 7 are equally represented among the primes to that point.
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%I #10 Mar 12 2015 00:26:12

%S 2,3,5,7,11,13,17,139,181,199,211,223,227,823,1093,1373,2713,2741,

%T 2753,9041,9619,9623,9743,9749,21467,21503,21529,260017,6399433,

%U 59998271,1404351607

%N Prime numbers after which at least four distinct classes modulo 7 are equally represented among the primes to that point.

%C Only after 13 and 223 are five of the congruence classes modulo 7 equally represented, and it's not unreasonable to conjecture that this holds permanently.

%e At the 31st term, 1404351607, 11698330 primes have occurred congruent to each of 1, 2, 3 and 4 modulo 7.

%t t = {}; mdCnt = {0, 0, 0, 0, 0, 0, 0}; Do[p = Prime[i]; mdCnt[[Mod[p, 7] + 1]]++; ty = Tally[mdCnt]; If[Select[ty, #[[2]] >= 4 &] != {}, AppendTo[t, p]], {i, 100000}]; t (* _T. D. Noe_, Sep 27 2012 *)

%K nonn

%O 1,1

%A _James G. Merickel_, Sep 27 2012