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%I #14 Jun 01 2019 09:31:16
%S 0,0,5,49,356,2678,21085,166814,1345812,11080939,92699035,786630700,
%T 6757485506
%N Number of consecutive runs of 3 odd nonprimes congruent to 3 mod 4 below 10^n.
%F Generate the odd nonprime sequence with nonprimes labeled 1 mod 4 or 3 mod 4. Add count of nonprimes to sequence if 3 nonprimes congruent to 3 mod 4 occur before interruption of a nonprime congruent to 1 mod 4
%e a(3)=5 because 5 nonprime runs of 3 occur below 10^3, each run interrupted by a nonprime congruent to 1 mod 4.
%t A091113 = Select[4 Range[0, 10^4] + 1, ! PrimeQ[#] &];
%t A091236 = Select[4 Range[0, 10^4] + 3, ! PrimeQ[#] &];
%t lst = {}; Do[If[Length[s = Select[A091236, Between[{A091113[[i]], A091113[[i + 1]]}]]] == 3, AppendTo[lst, Last[s]]], {i, Length[A091113] - 1}]; Table[Count[lst, x_ /; x < 10^n], {n, 4}] (* _Robert Price_, May 31 2019 *)
%Y Cf. A093183, A093184, A093185, A093186, A093187, A093397, A093398, A093399, A092643.
%K more,nonn
%O 1,3
%A _Enoch Haga_, Mar 30 2004
%E a(9)-a(13) from _Bert Dobbelaere_, Dec 19 2018
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