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%I #7 Apr 19 2020 23:43:05
%S 0,12,112,2296,64112,3104544,255353744,36091542548,8990276037592,
%T 3911658481295924,3022669494445395808,4128305052223833006600,
%U 10045914708457218016317000,43496963453603913793217952196
%N Number of n X n 0..2 arrays with some element plus some horizontally, vertically, diagonally or antidiagonally adjacent neighbor totalling two exactly once.
%C Diagonal of A268774.
%H R. H. Hardin, <a href="/A268767/b268767.txt">Table of n, a(n) for n = 1..17</a>
%e Some solutions for n=4
%e ..0..1..0..0. .1..2..2..2. .2..2..2..2. .0..1..0..0. .1..0..0..0
%e ..0..0..1..0. .1..2..2..2. .2..2..2..2. .1..0..0..0. .0..0..1..0
%e ..0..0..0..0. .2..2..2..2. .2..2..2..1. .0..0..0..0. .1..0..0..0
%e ..0..1..0..0. .2..1..2..2. .2..2..2..1. .1..0..1..0. .1..0..0..1
%Y Cf. A268774.
%K nonn
%O 1,2
%A _R. H. Hardin_, Feb 13 2016
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