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 A172240 #13 Mar 30 2012 18:40:08 %S A172240 3,7,13,17,19,29,31,37,41,43,53,61,67,71,73,79,83,89,97,101,103,109, %T A172240 113,127,131,137,139,149,151,157,163,173,181,191,193,197,199,211,223, %U A172240 229,233,239,241,251,257,263,269,271 %N A172240 Odd primes not in A181669. %C A172240 Except for term 5, the sequence contains all greater of twin primes %Y A172240 Cf. A001359, A173176, A172487, A181669, A181602, A173641. %K A172240 nonn,easy %O A172240 1,1 %A A172240 _Giovanni Teofilatto_, Nov 20 2010