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 A153802 #6 Mar 02 2020 00:52:06 %S A153802 0,0,0,0,2,6,8,22,87,163,198,257 %N A153802 a(n) = A153800(n) - A000040(n). %Y A153802 Cf. A000040, A000043, A000668, A000225, A000396, A007691, A153800, A153801, A153803. %K A153802 nonn,more %O A153802 1,5 %A A153802 _Omar E. Pol_, Jan 13 2009 %E A153802 a(11)-a(12) from _Jinyuan Wang_, Mar 01 2020