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%I #5 Mar 31 2012 12:36:19
%S 42,334,4449,97424,3388130,187160348,16551136352,2348378261899,
%T 533921776093322,194297764330364986,113166821986252773490,
%U 105535296084137818939844,157606962038222415838019755
%N Number of (n+2)X(n+2) symmetric binary matrices without the pattern 1 0 1 vertically or horizontally
%H R. H. Hardin, <a href="/A190602/b190602.txt">Table of n, a(n) for n = 1..17</a>
%e Some solutions for 4X4
%e ..1..1..1..1....0..1..1..0....1..0..0..0....1..1..1..0....0..0..0..0
%e ..1..1..1..1....1..1..0..0....0..1..1..1....1..0..0..0....0..1..0..0
%e ..1..1..1..1....1..0..0..0....0..1..1..0....1..0..0..1....0..0..1..0
%e ..1..1..1..0....0..0..0..1....0..1..0..0....0..0..1..0....0..0..0..1
%K nonn
%O 1,1
%A _R. H. Hardin_ May 13 2011
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