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 A089837 #6 Mar 31 2012 14:02:17 %S A089837 1,0,19,21,17,18,20,15,13,16,14,12,11,8,10,7,9,4,5,2,6,3,220,228,212, %T A089837 213,221,225,218,224,206,207,219,226,208,227,214,215,209,211,223,210, %U A089837 216,217,222,243,251,235,236,244,248,241,247,229,230,242,249,231,250 %N A089837 Involution of nonnegative integers: column 1 of A089839. %H A089837 A. Karttunen, <a href="/A089839/a089839.c.txt">C-program for computing the initial terms of this sequence</a> %H A089837 <a href="/index/Per#IntegerPermutation">Index entries for sequences that are permutations of the natural numbers</a> %Y A089837 Cf. A089838, A089843. %K A089837 nonn %O A089837 0,3 %A A089837 _Antti Karttunen_, Dec 05 2003