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.
%I A176821 #3 Mar 30 2012 18:52:40 %S A176821 5,11,13,7,29,59,61,31,659,1319,1321,661,809,1619,1621,811,2129,4259, %T A176821 4261,2131,2549,5099,5101,2551,3329,6659,6661,3331,3389,6779,6781, %U A176821 3391,5849,11699,11701,5851,6269,12539,12541,6271,10529,21059,21061,10531 %N A176821 List of 4-tuples of twin primes q, p, p+2 and q+2 such that 2*q<p<p+2<2*(q+2). %C A176821 The first number q in each quadruplet is in A069142 (equivalent to selecting twin primes q which are also Sophie-Germain primes). [From _R. J. Mathar_, May 06 2010] %Y A176821 Cf. A077800, A045536. %K A176821 nonn,tabf %O A176821 1,1 %A A176821 _Juri-Stepan Gerasimov_, Apr 26 2010, May 01 2010, May 07 2010 %E A176821 Corrected (2131 replaced by 3331) by _R. J. Mathar_, May 06 2010