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%I #6 Apr 20 2020 19:55:05
%S 0,240,385200,4410058320,446901694424400,431802177781617762960,
%T 4120579270516550893026428880,396051988194462616335989531581823280,
%U 388077749523667550173285586776073430011586480
%N Number of n X n 0..4 arrays with some element plus some horizontally or vertically adjacent neighbor totalling four exactly once.
%C Diagonal of A270058.
%e Some solutions for n=2
%e ..1..2. .0..3. .2..2. .1..1. .3..0. .1..2. .1..0. .0..4. .1..0. .2..3
%e ..3..4. .0..1. .4..1. .4..3. .2..2. .4..0. .3..2. .0..2. .1..4. .2..3
%Y Cf. A270058.
%K nonn
%O 1,2
%A _R. H. Hardin_, Mar 09 2016
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