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 A253884 #5 Jan 17 2015 23:42:19 %S A253884 1,2,8,4,24,5,8192,3,64,512,393216,32,7077888,320,384,6, %T A253884 3802951800684688204490109616128,15,300578991243264,11,1073741824, %U A253884 5184,1134000,128,100,1664,27,864,392318858461667547739736838950479151006397215279002157056000,65536,9822276308431282926640601754292746977280,16,1215 %N A253884 Permutation of natural numbers: a(n) = A122111(A243506(n)). %H A253884 <a href="/index/Per#IntegerPermutation">Index entries for sequences that are permutations of the natural numbers</a> %F A253884 a(n) = A122111(A243506(n)). %o A253884 (Scheme) (define (A253884 n) (A122111 (A243506 n))) %Y A253884 Inverse: A253883. %Y A253884 Similar permutations: A253792, A253892, A122111, A243506. %K A253884 nonn %O A253884 1,2 %A A253884 _Antti Karttunen_, Jan 17 2015