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 A344547 #8 Jun 04 2021 22:48:59 %S A344547 0,1,3,2,5,4,7,6,8,9,10,12,11,14,16,18,13,20,22,24,15,26,28,30,32,17, %T A344547 34,36,38,40,19,42,44,46,48,50,21,52,54,56,58,60,23,62,64,66,68,70,72, %U A344547 25,74,76,78,80,82,84,27,86,88,90,92,94,96,98,29,100,102,104,106,108,110,112,31,114 %N A344547 Lexicographically earliest sequence of nonnegative terms forming a clockwise square spiral when nothing else is read except the parity of the terms (see the Comments section). %C A344547 An even term turns the pencil 0 degrees to the right, then advances 1 unit; an odd term turns the pencil 90 degrees to the right, then advances 1 unit. %e A344547 The pencil points towards the East before the start. The 0 doesn't change its orientation and a 1-unit line directed towards the East is traced. As 1 is odd, the pencil turns 90 degrees towards the South and a 1-unit line is traced. As 3 is odd, the pencil turns 90 degrees towards the West and a 1-unit line is traced. As 2 is even, the pencil doesn't change its orientation (towards the West) and a 1-unit line is traced. As 5 is odd, the pencil turns 90 degrees towards the North and a 1-unit line is traced. As 4 is even, the pencil doesn't change its orientation (towards the North) and a 1-unit line is traced. Etc. %Y A344547 Cf. A344548 (same idea with digits), A174344 (an example of a clockwise square spiral). %K A344547 base,nonn %O A344547 1,3 %A A344547 _Eric Angelini_ and _Carole Dubois_, Jun 04 2021