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 A050005 #6 Aug 06 2021 07:06:10 %S A050005 1,3,9,15,2,8,11,14,27,4,30,7,33,66,10,36,13,59,26,16,72,29,105,52,6, %T A050005 75,32,65,161,55,22,35,184,121,12,164,58,25,48,38,187,124,71,114,28, %U A050005 220,104,51,94,5,190,74,243,180,31,64,107,286,160 %N A050005 a(n) = position of n in A050004. %Y A050005 Cf. A050004. %K A050005 nonn,easy %O A050005 1,2 %A A050005 _Clark Kimberling_