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%I #11 Apr 01 2022 09:14:04
%S 0,1,1,-1,0,2,2,0,-2,1,3,3,-1,-3,-3,0,4,4,2,-2,-4,-4,-3,3,5,5,3,-1,-3,
%T -5,0,4,6,6,2,0,-6,-6,-6,-3,3,5,7,7,7,5,-7,-7,-6,-4,0,6,8,8,8,2,-4,-6,
%U -8,-8,-8,-5,9,9,9,9,3,-3,-9,-9,-9,-9,-4,2,8,10
%N The y-coordinates of prime numbers in an Ulam spiral oriented counterclockwise with first step east.
%C 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.
%H William Rex Marshall, <a href="/A214665/b214665.txt">Table of n, a(n) for n = 1..10077</a> (coordinates of primes in a 325 X 325 square).
%H Scientific American, <a href="https://www.jstor.org/stable/24936037">Front Matter</a>, Vol. 210, No. 3, March 1964.
%Y Cf. A000040, A063826, A214664, A214666, A214667.
%K sign,easy
%O 1,6
%A _William Rex Marshall_, Jul 26 2012
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