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 A194037 #8 Mar 19 2022 00:24:03 %S A194037 1,3,6,10,15,2,5,9,14,20,21,28,4,8,13,19,26,27,35,36,45,7,12,18,25,33, %T A194037 34,43,44,54,55,66,11,17,24,32,41,42,52,53,64,65,77,78,91,16,23,31,40, %U A194037 50,51,62,63 %N A194037 Inverse permutation to A194036; contains every positive integer exactly once. %t A194037 (See A194036.) %Y A194037 Cf. A194036. %K A194037 nonn %O A194037 0,2 %A A194037 _Clark Kimberling_, Aug 12 2011