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%I #10 Aug 30 2015 10:11:12
%S 1,2,3,4,5,6,8,9,10,11,12,15,16,18,20,22,23,24,25,27,29,30,32,33,36,
%T 40,41,44,45,46,48,50,53,54,55,58,60,64,66,69,72,75,80,81,82,83,87,88,
%U 89,90,92,96,99,100,106,108,110,113,115,116,120,121,123,125,128,131,132
%N Multiplicative closure of Sophie Germain primes (A005384).
%C A156542(a(n)) = A001221(a(n));
%C Subsequence of A130176.
%H R. Zumkeller, <a href="/A156541/b156541.txt">Table of n, a(n) for n = 1..1000</a>
%t Select[Range@132, And @@ PrimeQ[FactorInteger[#][[All, 1]]*2 + 1] &] (* _Ivan Neretin_, Aug 30 2015 *)
%Y Cf. A156541, A156543.
%K nonn
%O 1,2
%A _Reinhard Zumkeller_, Feb 10 2009
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