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 A190419 Number of (n+2)X(n+2) symmetric binary matrices without the pattern 1 1 1 diagonally 1

%I

%S 56,728,17472,768768,62270208,9278260992,2542243511808,

%T 1281290729951232,1187756506664792064,2025124843863470469120,

%U 6350791510355843391160320,36631365431732504680212725760,388622155865250142152376807587840

%N Number of (n+2)X(n+2) symmetric binary matrices without the pattern 1 1 1 diagonally

%H R. H. Hardin, <a href="/A190419/b190419.txt">Table of n, a(n) for n = 1..62</a>

%e Some solutions for n=2

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

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

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

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

%K nonn

%O 1,1

%A _R. H. Hardin_ May 10 2011

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Last modified November 27 22:56 EST 2022. Contains 358406 sequences. (Running on oeis4.)