A268791 - OEIS

A268791

Number of n X n 0..2 arrays with some element plus some horizontally, vertically or antidiagonally adjacent neighbor totalling two exactly once.

%I #7 Apr 19 2020 23:43:47

%S 0,22,248,4800,168740,11138352,1384570516,325815151556,

%T 145913571668076,124768928833331732,204377241703937153076,

%U 642788798787566885184552,3889478620658657294120765368,45350632160719542617837369658508

%N Number of n X n 0..2 arrays with some element plus some horizontally, vertically or antidiagonally adjacent neighbor totalling two exactly once.

%C Diagonal of A268798.

%H R. H. Hardin, <a href="/A268791/b268791.txt">Table of n, a(n) for n = 1..18</a>

%e Some solutions for n=4

%e ..1..0..0..0. .2..1..2..1. .2..2..1..0. .1..2..1..2. .2..2..2..1

%e ..1..0..1..0. .2..2..2..2. .1..0..0..0. .2..2..2..2. .2..1..2..2

%e ..0..0..0..0. .2..2..2..2. .0..1..0..1. .2..1..2..1. .2..2..2..1

%e ..1..0..0..0. .1..2..1..1. .0..0..0..0. .2..1..2..2. .2..2..2..1

%Y Cf. A268798.

%K nonn

%O 1,2

%A _R. H. Hardin_, Feb 13 2016