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 A030568 #7 Apr 03 2020 20:29:23 %S A030568 0,6,18,30,42,54,66,67,70,73,76,79,82,84,102,120,138,156,174,175,178, %T A030568 181,184,187,190,192,210,228,246,264,282,283,286,289,292,295,298,300, %U A030568 318,336,354,372,390,391,394,397,400,403,406,408 %N A030568 Position of n-th 0 in A030567. %K A030568 nonn %O A030568 1,2 %A A030568 _Clark Kimberling_ %E A030568 Initial 0 inserted for consistency with change in A030567 by _Sean A. Irvine_, Apr 03 2020