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 A168497 #8 Jun 18 2015 09:30:37 %S A168497 1,2,3,6,9,15,21,30,36,51,54,69,75,90,96,99,114,120,135,141,156,174, %T A168497 210,216,231,261,285,300,309,321,330,405,411,414,429,441,510,516,525, %U A168497 531,546,576,615,639,645,651,660,714,726,741,744,804,810,834,849,861,894 %N A168497 The halfs of even single (or even isolated) numbers. %C A168497 Essentially the same as A040040: 1, followed by A040040. - _Joerg Arndt_, Jun 18 2015 %C A168497 Even single (or isolated) numbers/2. Unit together with (average of twin prime pairs (A014574), divided by 2). %F A168497 a(n)=A167777(n)/2. %Y A168497 Cf. A040040, A167777. %K A168497 nonn %O A168497 1,2 %A A168497 _Juri-Stepan Gerasimov_, Nov 27 2009 %E A168497 Entries checked by _R. J. Mathar_, Apr 14 2010