A221389 - OEIS

A221389

Number of 3 X n arrays of occupancy after each element moves to some horizontal or antidiagonal neighbor, with no 2-loops and with no occupancy greater than 2.

%I #6 Apr 25 2023 13:58:24

%S 0,0,4,94,1450,20689,284702,3856027,51806212,693213401,9256626752,

%T 123474805622,1646142914632,21939928353674,292375085482054,

%U 3895949812693799,51912242778609770,691699897071467742

%N Number of 3 X n arrays of occupancy after each element moves to some horizontal or antidiagonal neighbor, with no 2-loops and with no occupancy greater than 2.

%C Row 3 of A221388.

%H R. H. Hardin, <a href="/A221389/b221389.txt">Table of n, a(n) for n = 1..37</a>

%e All solutions for n=3

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

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

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

%Y Cf. A221388.

%K nonn

%O 1,3

%A _R. H. Hardin_, Jan 14 2013