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 A381489 #22 Mar 21 2025 02:24:18 %S A381489 0,0,1,1,2,2,3,3,0,0,1,1,2,2,3,3,4,4,5,5,6,6,7,7,4,4,5,5,6,6,7,7,0,0, %T A381489 1,1,2,2,3,3,0,0,1,1,2,2,3,3,4,4,5,5,6,6,7,7,4,4,5,5,6,6,7,7,0,0,1,1, %U A381489 2,2,3,3,0,0,1,1,2,2,3,3,4,4,5,5,6,6,7,7,4,4,5,5,6,6,7,7 %N A381489 Index of first half of decomposition of integers into pairs x(i)+y(j) based on A380008 and A380009, respectively. %C A381489 One coordinate of a recursive non-self-intersecting walk on the square lattice Z^2. %C A381489 Every integer appears infinitely many times in the sequence. %H A381489 Luis Rato, <a href="/A380009/a380009.png">Plot of an NZ-order curve</a>, containing the integers from 0 to 255. %H A381489 <a href="/index/Con#coordinates_2D_curves">Index entries for sequences related to coordinates of 2D curves</a> %F A381489 n = A380008(a(n)) + A380009(A381490(n)). %e A381489 A380008(a(14)) + A380009(A381490(14)) = A380008(3) + A380009(2) = 6+8 = 14. %Y A381489 Cf. A380008, A380009, A381490. %K A381489 easy,nonn %O A381489 0,5 %A A381489 _Luis Rato_, Feb 25 2025