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 A072741 #2 May 01 2014 02:47:42 %S A072741 0,0,1,0,2,3,0,0,4,5,0,0,1,6,7,0,0,1,2,8,9,0,0,1,3,4,10,11,0,0,1,1,5, %T A072741 6,12,13,0,0,1,1,2,7,8,14,15,0,0,1,1,2,3,9,10,16,17,0,0,1,1,2,4,5,11, %U A072741 12,18,19,0,0,1,1,2,2,6,7,13,14,20,21,0,0,1,1,2,2,3,8,9,15,16,22,23,0,0,1 %N A072741 Y-projection of the tabular N X N -> N bijection A072734. %o A072741 (Scheme) (define (A072741 n) (A002262 (A072735 n))) %Y A072741 The X-projection is A072740. Composition of A002262 & A072735. A072784(n) = A072741(n)-A072737(n). %K A072741 nonn,tabl %O A072741 0,5 %A A072741 _Antti Karttunen_, Jun 12 2002