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 A252458 #4 Dec 17 2014 20:53:47 %S A252458 8,13,14,34,139,140,383,960,1609,2064,5487,7171,7715,21059,22523, %T A252458 24148,91924,117728,200193,304381,609147,866933,920405,930571,985939 %N A252458 Fixed points of permutations A249990 and A252448. %C A252458 A249990(a(n)) = A252448(a(n)) = a(n). %o A252458 (Haskell) %o A252458 a252458 n = a252458_list !! (n-1) %o A252458 a252458_list = [x | x <- [1..], a249990 x == x] %Y A252458 Cf. A249990, A252448. %K A252458 nonn %O A252458 1,1 %A A252458 _Reinhard Zumkeller_, Dec 17 2014