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 A178733 #5 Aug 02 2015 12:55:26 %S A178733 0,6,12,22,24,38,44,54,48,54,76,70,88,86,108,102,96,102,108,150,152, %T A178733 134,140,182,176,182,172,166,216,214,204,198,192,198,204,214,216,294, %U A178733 300,310,304,310,268,262,280,278,364,358,352,358,364,342,344,326,332,438 %N A178733 a(n) = n XOR 7n, where XOR is bitwise XOR. %t A178733 f[n_] := BitXor[n, 7 n]; Array[f, 60, 0] (* _Robert G. Wilson v_, Jun 09 2010 *) %Y A178733 Cf. A048724, A178729, A048725, A178731, A178732, A178734, A178735, A178736. - _Robert G. Wilson v_, Jun 09 2010 %K A178733 nonn %O A178733 0,2 %A A178733 _Dmitry Kamenetsky_, Jun 08 2010 %E A178733 a(30) onwards from _Robert G. Wilson v_, Jun 09 2010