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 A072737 #3 May 01 2014 02:47:42 %S A072737 0,0,2,0,1,4,0,0,3,6,0,0,1,5,8,0,0,1,3,7,10,0,0,1,2,5,9,12,0,0,1,1,4, %T A072737 7,11,14,0,0,1,1,2,6,9,13,16,0,0,1,1,2,4,8,11,15,18,0,0,1,1,2,3,6,10, %U A072737 13,17,20,0,0,1,1,2,2,5,8,12,15,19,22,0,0,1,1,2,2,3,7,10,14,17,21,24,0,0 %N A072737 Y-projection of the tabular N X N -> N bijection A072732. %o A072737 (Scheme) (define (A072737 n) (A002262 (A072733 n))) %Y A072737 The X-projection is A072736. Composition of A002262 and A072733. A072784(n) = A072741(n)-A072737(n). %K A072737 nonn,tabl %O A072737 0,3 %A A072737 _Antti Karttunen_, Jun 12 2002