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 A205400 #5 Mar 30 2012 18:58:11 %S A205400 1,3,2,5,4,2,8,7,5,3,11,10,8,6,3,15,14,12,10,7,4,19,18,16,14,11,8,4, %T A205400 24,23,21,19,16,13,9,5,29,28,26,24,21,18,14,10,5,35,34,32,30,27,24,20, %U A205400 16,11,6,41,40,38,36,33,30,26,22,17,12,6,48,47,45,43,40,37,33 %N A205400 Ordered differences of quarter-squares. %C A205400 For a guide to related sequences, see A204892. %e A205400 a(1)=s(2)-s(1)=2-1=1 %e A205400 a(2)=s(3)-s(1)=4-1=3 %e A205400 a(3)=s(3)-s(2)=4-2=2 %e A205400 a(4)=s(4)-s(1)=6-1=5 %e A205400 a(5)=s(4)-s(2)=6-2=4 %t A205400 (See the program at A205402.) %Y A205400 Cf. A205402, A204892. %K A205400 nonn %O A205400 1,2 %A A205400 _Clark Kimberling_, Jan 27 2012