A190537 - OEIS

%I #5 Mar 31 2012 12:36:19

%S 39,276,2462,30347,497319,11215564,345643238,14729798587,868126086355,

%T 71051142699591,8082717906091557,1279982834102896086,

%U 282345340720841681874,86807291886729731363231

%N Number of (n+2)X(n+2) symmetric binary matrices without the pattern 0 1 1 diagonally, vertically or horizontally

%H R. H. Hardin, <a href="/A190537/b190537.txt">Table of n, a(n) for n = 1..17</a>

%e Some solutions for 4X4

%e ..1..1..1..0....0..0..0..1....1..1..0..0....0..1..0..1....1..0..0..1

%e ..1..0..1..0....0..1..0..1....1..1..1..0....1..1..1..1....0..0..0..1

%e ..1..1..0..0....0..0..0..0....0..1..0..1....0..1..0..0....0..0..0..0

%e ..0..0..0..0....1..1..0..0....0..0..1..0....1..1..0..0....1..1..0..0

%K nonn

%O 1,1

%A _R. H. Hardin_ May 12 2011