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 A030756 #8 Apr 09 2020 01:33:28 %S A030756 1,11,28,38,60,88,91,107,109,131,153,206,267,302,379,429,477,518,522, %T A030756 527,570,572,580,633,637,692,747,755,760,826,889,892,897,957,971,1021, %U A030756 1035,1041,1043,1046,1114,1115,1203,1207,1291,1362,1369,1382,1467,1469 %N A030756 Numbers k such that A030747(k)=4. %K A030756 nonn %O A030756 1,2 %A A030756 _Clark Kimberling_ %E A030756 More terms from _Sean A. Irvine_, Apr 08 2020