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 A178734 #9 Jun 30 2022 08:39:37 %S A178734 0,9,18,27,36,45,54,63,72,65,90,83,108,101,126,119,144,153,130,139, %T A178734 180,189,166,175,216,209,202,195,252,245,238,231,288,297,306,315,260, %U A178734 269,278,287,360,353,378,371,332,325,350,343,432,441,418,427,404,413,390 %N A178734 a(n) = n XOR 8n, where XOR is bitwise XOR. %t A178734 f[n_] := BitXor[n, 8 n]; Array[f, 60, 0] (* _Robert G. Wilson v_, Jun 09 2010 *) %o A178734 (Python) %o A178734 def A178734(n): return n^ n<<3 # _Chai Wah Wu_, Jun 29 2022 %Y A178734 Cf. A048724, A178729, A048725, A178731, A178732, A178733, A178735, A178736. - _Robert G. Wilson v_, Jun 09 2010 %K A178734 nonn %O A178734 0,2 %A A178734 _Dmitry Kamenetsky_, Jun 08 2010 %E A178734 a(30) onwards from _Robert G. Wilson v_, Jun 09 2010