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 A194047 #8 Mar 19 2022 00:24:23 %S A194047 1,3,6,10,2,5,9,14,15,4,8,13,19,20,21,7,12,18,25,26,27,28,11,17,24,32, %T A194047 33,34,35,36,16,23,31,40,41,42,43,44,45,22,30,39,49,50,51,52,53,54,55, %U A194047 29,38,48,59,60,61,62,63,64,65,66,37,47,58,70,71,72,73,74,75 %N A194047 Inverse permutation to A194046; contains every positive integer exactly once. %t A194047 (See A194046.) %Y A194047 Cf. A194046. %K A194047 nonn %O A194047 1,2 %A A194047 _Clark Kimberling_, Aug 13 2011