cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A130176 Numbers n with property that the largest prime factor is a Sophie Germain prime.

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%I A130176 #12 Aug 30 2015 11:44:39
%S A130176 2,3,4,5,6,8,9,10,11,12,15,16,18,20,22,23,24,25,27,29,30,32,33,36,40,
%T A130176 41,44,45,46,48,50,53,54,55,58,60,64,66,69,72,75,77,80,81,82,83,87,88,
%U A130176 89,90,92,96,99,100,106,108,110,113,115,116,120,121,123,125,128,131,132
%N A130176 Numbers n with property that the largest prime factor is a Sophie Germain prime.
%C A130176 Prime terms 2,3,5,11,23,29,... are in A005384.
%C A130176 A156541 is a subsequence. [_Reinhard Zumkeller_, Feb 10 2009]
%C A130176 A156660(A006530(a(n))) = 1. [_Reinhard Zumkeller_, Dec 03 2009]
%t A130176 Select[Range[2, 132], PrimeQ[FactorInteger[#][[-1, 1]]*2 + 1] &] (* _Ivan Neretin_, Aug 30 2015 *)
%Y A130176 Cf. A005384.
%K A130176 nonn
%O A130176 1,1
%A A130176 _Zak Seidov_, May 14 2007