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 A257502 #7 Mar 22 2022 00:11:48 %S A257502 0,1,4,2,7,10,3,5,13,16,19,22,25,6,8,28,31,34,37,40,43,46,49,52,55,9, %T A257502 11,58,61,64,67,70,73,76,79,82,85,88,91,94,97,100,103,106,109,112,115, %U A257502 118,12,14,121,124,127,130,133,136,139,142,145,148,151,154 %N A257502 Inverse permutation to A078783. %H A257502 Reinhard Zumkeller, <a href="/A257502/b257502.txt">Table of n, a(n) for n = 0..10000</a> %o A257502 (Haskell) %o A257502 import Data.List (elemIndex); import Data.Maybe (fromJust) %o A257502 a257502 = fromJust . (`elemIndex` a078783_list) %Y A257502 Cf. A078783. %K A257502 nonn %O A257502 0,3 %A A257502 _Reinhard Zumkeller_, May 01 2015