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A341631 Numbers k such that A073837(k) is prime.

%I A341631 #9 Feb 17 2021 10:53:32
%S A341631 2,7,9,14,19,27,28,29,30,36,44,60,61,68,70,71,87,88,89,100,101,104,
%T A341631 105,108,109,112,113,138,157,174,192,193,199,201,202,203,204,210,274,
%U A341631 275,276,277,304,305,306,364,365,366,372,373,384,387,388,389,399,400,401,405,471,472,473,511,512,513
%N A341631 Numbers k such that A073837(k) is prime.
%C A341631 Numbers k such that the sum of primes from k to 2*k is prime.
%H A341631 Robert Israel, <a href="/A341631/b341631.txt">Table of n, a(n) for n = 1..10000</a>
%e A341631 a(3) = 9 is in the sequence because A073837(9) = 11+13+17 = 41 is prime.
%p A341631 R:= 2: S:= [2, 3]: s:= 5: q:= 5: count:= 1:
%p A341631 for n from 3 while count < 100 do
%p A341631   if n = S[1]+1 then S:= S[2..-1]; s:= s-n+1 fi;
%p A341631   if q <= 2*n then S:= [op(S), q]; s:= s+q; q:= nextprime(q) fi;
%p A341631   if isprime(s) then count:= count+1; R:= R, n;  fi;
%p A341631 od:
%p A341631 R;
%Y A341631 Cf. A073837, A341280, A341632.
%K A341631 nonn
%O A341631 1,1
%A A341631 _J. M. Bergot_ and _Robert Israel_, Feb 16 2021