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 A066682 #13 Aug 19 2022 15:10:34 %S A066682 0,1,2,0,3,0,4,5,0,0,6,7,8,0,0,0,9,10,11,0,0,0,12,0,0,0,13,0,14,15,16, %T A066682 0,0,0,0,0,17,0,0,0,18,0,19,0,20,0,21,0,0,22,0,0,23,0,0,0,0,0,24,0,25, %U A066682 0,26,0,0,0,27,0,0,28,29,0,30,0,31,0,0,0,32 %N A066682 Indices of badly sieved numbers: a(n) = k if n = A066680(k), otherwise 0. %F A066682 a(n) = A099104(n)*A066683(n). %Y A066682 Cf. A049084, A066680, A066683, A099104. %K A066682 nonn %O A066682 1,3 %A A066682 _Reinhard Zumkeller_, Dec 31 2001