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 A214666 #7 Jul 26 2012 12:03:30 %S A214666 -1,-1,1,1,-2,-2,2,2,0,-3,-3,3,3,3,-1,-4,-2,0,4,4,4,-2,-5,-5,1,5,5,5, %T A214666 5,3,-6,-6,-2,0,6,6,6,0,-4,-7,-7,-7,1,3,7,7,7,-5,-8,-8,-8,-8,-8,2,8,8, %U A214666 8,8,4,0,-2,-9,-9,-5,-3,1,9,9,5,3,-1,-7,-10,-10,-10 %N A214666 The x-coordinates of prime numbers in an Ulam spiral oriented counterclockwise with first step west. %C A214666 The eight possible orientations of the Ulam spiral can be derived from combining either A214664 or A214666 with either A214665 or A214667 as ordered pairs of coordinates. %C A214666 This spiral is rotated 180 degrees from the spiral on the March 1964 cover of Scientific American. %H A214666 William Rex Marshall, <a href="/A214666/b214666.txt">Table of n, a(n) for n = 1..10077</a> (coordinates of primes in a 325 X 325 square) %Y A214666 Cf. A000040, A063826, A214664, A214665, A214667. %K A214666 sign,easy %O A214666 1,5 %A A214666 _William Rex Marshall_, Jul 26 2012