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 A247204 #7 Dec 10 2014 23:59:20 %S A247204 1,2,3,4,10,45,46,47,48,49,50,71,72,73,74,75,80,90,91,92,93,185,186, %T A247204 187,188,189,194,195,199,205,206,207,210,211,212,213,214,217,218,219, %U A247204 220,221,232,233,239,288,289,290,291,292,328,329,330,336,337,338,339 %N A247204 Fixed points of permutations A250552 and A250553. %C A247204 A250552(a(n)) = A250553(a(n)) = a(n). %H A247204 Reinhard Zumkeller, <a href="/A247204/b247204.txt">Table of n, a(n) for n = 1..10000</a> %o A247204 (Haskell) %o A247204 a247204 n = a247204_list !! (n-1) %o A247204 a247204_list = filter ((zipWith (==) [1..] a250552_list) !!) [1..] %Y A247204 Cf. A250552, A250553. %K A247204 nonn %O A247204 1,2 %A A247204 _Reinhard Zumkeller_, Dec 10 2014