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 A064877 #3 Mar 30 2012 18:50:18 %S A064877 0,0,0,0,2,2,2,2,4,6,6,6,6,8,8,8,12,12,12,12,14,14,14,14,16,20,20,20, %T A064877 20,22,22,22,24,24,26,26,30,30,30,30,32,32,32,32,34,36,36,36,36,42,42, %U A064877 42,42,44,44,44,44,46,48,48,48,50,50,50,56,56,56,54,58,58,56,56,60,62 %N A064877 a(n) = n - (A064873(n) + A064874(n) + A064875(n) + A064876(n)). %Y A064877 Cf. A064873, A064874, A064875, A064876. %K A064877 nonn %O A064877 0,5 %A A064877 _Reinhard Zumkeller_, Oct 10 2001