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 A072736 #2 May 01 2014 02:47:42 %S A072736 0,1,0,3,0,0,5,2,0,0,7,4,1,0,0,9,6,2,1,0,0,11,8,4,1,1,0,0,13,10,6,3,1, %T A072736 1,0,0,15,12,8,5,2,1,1,0,0,17,14,10,7,3,2,1,1,0,0,19,16,12,9,5,2,2,1, %U A072736 1,0,0,21,18,14,11,7,4,2,2,1,1,0,0,23,20,16,13,9,6,3,2,2,1,1,0,0,25,22 %N A072736 X-projection of the tabular N X N -> N bijection A072732. %o A072736 (Scheme) (define (A072736 n) (A025581 (A072733 n))) %Y A072736 The Y-projection is A072737. Composition of A025581 & A072733. A072783(n) = A072740(n)-A072736(n). %K A072736 nonn,tabl %O A072736 0,4 %A A072736 _Antti Karttunen_, Jun 12 2002