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 A307196 #10 Mar 30 2019 18:08:34 %S A307196 0,1,0,2,1,0,1,0,1,0,1,0,1,0,1,0,2,1,0,1,0,1,0,1,0,1,0,1,0,1,0,1,0,1, %T A307196 0,1,0,2,1,0,1,0,1,0,1,0,1,0,1,0,1,0,1,0,1,0,1,0,1,0,1,0,1,0,1,0,2,1, %U A307196 0,1,0,1,0,1,0,1,0,1,0,1,0,1,0,1,0,1,0,1,0,1,0,1,0,1,0,1,0,1,0,1,0,1,0,2,1,0 %N A307196 Fill the plane with the square spiral with cells numbered as in A275609; sequence gives the cells along the North-West spoke starting at the origin. %C A307196 The Example section of A275609 shows the central portion of the spiral very clearly. The link below shows a larger portion but is harder to read. %H A307196 Alois P. Heinz, <a href="/A307196/b307196.txt">Table of n, a(n) for n = 0..1000</a> %H A307196 N. J. A. Sloane, <a href="/A275609/a275609.txt">Central portion of spiral, shown without spaces</a> [The central 0 (at (0,0)) has been changed to an X. The illustration shows cells (x,y) with -35 <= x <= 35, -33 <= y <= 36.] The present sequence gives the numbers to the North-West of the X. %Y A307196 Cf. A275609. %Y A307196 The eight spokes starting at the origin are A307193 - A307200. %K A307196 nonn %O A307196 0,4 %A A307196 _N. J. A. Sloane_, Mar 29 2019 %E A307196 More terms from _Alois P. Heinz_, Mar 30 2019