%I
%S 2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,
%T 28,30,31,32,33,34,36,38,39,40,42,43,44,46,47,48,49,51,52,56,57,60,62,
%U 64,66,67,68,69,72,75,76,78,80,84,86,88,92,93,94,96,100,102,104,112,114
%N Orders of Parker rings.
%C A field or ring is called "Parker" if no 3 X 3 magic square of 9 distinct squared elements can be formed. Conjecture: the sequence is complete.
%C Example: the fact that p=31 is listed is taken to mean one cannot construct a 3 X 3 magic square of distinct squared elements of the ring of order 31.
%H Onno M. Cain, <a href="https://github.com/onnomc/parkerringsearch">parkerringsearch SageMath code</a>, Apr 24, 2019.
%H Onno M. Cain, <a href="https://arxiv.org/abs/1908.03236">Gaussian Integers, Rings, Finite Fields and the Magic Square of Squares</a>, arXiv:1908.03236 [math.RA], 2019.
%H Matt Parker & Brady Haran, <a href="https://www.youtube.com/watch?v=aOT_bGvWyg">The Parker Square</a>, Numberphile video (2016).
%Y Cf. A308838 (for finite field).
%K nonn
%O 1,1
%A _Michel Marcus_, Aug 18 2019
