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 A030500 #7 Apr 02 2020 18:02:40 %S A030500 24,28,32,36,40,44,49,53,58,63,66,71,73,77,82,87,90,95,97,101,106,111, %T A030500 114,119,121,126,131,136,141,146,152,157,163,169,173,179,182,187,193, %U A030500 199,203,209,212,217,223,229,233,239,240,245,250,255,260,265,270,275 %N A030500 Position of n-th 4 in A030496. %K A030500 nonn %O A030500 1,1 %A A030500 _Clark Kimberling_ %E A030500 a(25) onward corrected by _Sean A. Irvine_, Apr 02 2020