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 A050101 #10 Jul 02 2021 01:55:54 %S A050101 1,31,3,12,21,30,36,42,48,2,8,11,14,17,20,23,26,29,208,32,211,35,38, %T A050101 78,41,44,118,47,84,4,155,87,7,158,90,10,56,93,263,13,59,96,16,300,62, %U A050101 19,201,269,402,22,102,204,25,306,68,28,207,241,275 %N A050101 a(n) is the position of n in A050100. %K A050101 nonn %O A050101 1,2 %A A050101 _Clark Kimberling_ %E A050101 Definition corrected by _Clark Kimberling_, Jul 01 2021