A268880 - OEIS

%I #7 Apr 19 2020 23:44:26

%S 0,5,84,4133,317966,55491832,19876401224,15564645769042,

%T 26617222097087230,99905925686618815012,832547140418699137884096,

%U 15355865014207234684746438192,632296902429868672596327438625296

%N Number of n X n binary arrays with some element plus some horizontally or antidiagonally adjacent neighbor totalling two exactly once.

%C Diagonal of A268886.

%H R. H. Hardin, <a href="/A268880/b268880.txt">Table of n, a(n) for n = 1..26</a>

%e Some solutions for n=4

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

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

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

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

%Y Cf. A268886.

%K nonn

%O 1,2

%A _R. H. Hardin_, Feb 15 2016