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%I #11 Mar 10 2020 18:00:48
%S 1,2,1,7,14,111,277,4630,25913,702227,6394908,326629617,5687827965,
%T 509730678546,15540557303649,2543316661538595,142034694045640208,
%U 41602235282780689163,4154045153554082019959,2201424142622929530965310
%N Number of n X n binary matrices, symmetric under 180 degree rotation, with no more than 1 one in any 2 X 2 subblock.
%H R. H. Hardin, Aug 09 2008, <a href="/A141488/b141488.txt">Table of n, a(n) for n = 0..24</a>
%H Yüksel Soykan, <a href="https://doi.org/10.9734/JAMCS/2019/v34i530224">Sum Formulas for Generalized Fifth-Order Linear Recurrence Sequences</a>, Journal of Advances in Mathematics and Computer Science (2019) Vol. 34, No. 5, 1-14.
%K nonn
%O 0,2
%A _R. H. Hardin_, Aug 09 2008