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 A054428 #6 Jul 10 2011 18:39:17 %S A054428 1,2,4,3,6,9,8,5,10,17,21,16,15,20,14,7,12,27,40,31,39,54,45,26,25,44, %T A054428 51,36,30,35,24,11,18,41,63,56,70,101,92,55,62,114,136,100,90,113,77, %U A054428 38,37,76,110,87,99,133,109,61,50,85,98,67,49,60,34,13,22,57,94,79,117 %N A054428 Inverse permutation to A054427. %H A054428 <a href="/index/Per#IntegerPermutation">Index entries for sequences that are permutations of the natural numbers</a> %p A054428 [seq(nthmember(j, A054427),j=1..200)]; # nthmember as in A054426 %K A054428 nonn %O A054428 1,2 %A A054428 Antti Karttunen