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Number of n X n 0..1 arrays with every 1 horizontally or antidiagonally adjacent to 2 neighboring 1's.
1

%I #7 Apr 19 2020 23:55:13

%S 1,1,3,10,49,495,13504,629563,40753529,4162842319,790491998237,

%T 268041967942170,155466640607601204,159960976273554094907,

%U 300474954115694463716874,1003924486221768324971576564

%N Number of n X n 0..1 arrays with every 1 horizontally or antidiagonally adjacent to 2 neighboring 1's.

%C Diagonal of A297299.

%H R. H. Hardin, <a href="/A297295/b297295.txt">Table of n, a(n) for n = 1..21</a>

%e Some solutions for n=5

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

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

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

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

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

%Y Cf. A297299.

%K nonn

%O 1,3

%A _R. H. Hardin_, Dec 27 2017