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Number of n X n 0..1 arrays with every element unequal to 0, 1, 5 or 8 king-move adjacent elements, with upper left element zero.
1

%I #7 Apr 20 2020 00:07:57

%S 1,1,6,21,146,1246,13767,252509,5755625,177353720,8354131403,

%T 523250794396,44173651472383,5428616779817049,920678621074132173,

%U 212277158481925445968,69198443091508695982216

%N Number of n X n 0..1 arrays with every element unequal to 0, 1, 5 or 8 king-move adjacent elements, with upper left element zero.

%C Diagonal of A304270.

%H R. H. Hardin, <a href="/A304264/b304264.txt">Table of n, a(n) for n = 1..22</a>

%e Some solutions for n=5

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

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

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

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

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

%Y Cf. A304270.

%K nonn

%O 1,3

%A _R. H. Hardin_, May 09 2018