cp's OEIS Frontend

A221323 Number of n X 3 arrays of occupancy after each element stays put or moves to some horizontal or antidiagonal neighbor, with no occupancy greater than 2.

%I A221323 #8 Aug 05 2018 08:21:51
%S A221323 7,119,2008,33873,571358,9637322,162555929,2741882383,46248186229,
%T A221323 780082534460,13157894317753,221938287447408,3743501973486176,
%U A221323 63142809559541159,1065049364666447387,17964518161956501475
%N A221323 Number of n X 3 arrays of occupancy after each element stays put or moves to some horizontal or antidiagonal neighbor, with no occupancy greater than 2.
%C A221323 Column 3 of A221328.
%H A221323 R. H. Hardin, <a href="/A221323/b221323.txt">Table of n, a(n) for n = 1..69</a>
%F A221323 Empirical: a(n) = 23*a(n-1) - 110*a(n-2) + 111*a(n-3) - 6*a(n-4) - 8*a(n-5).
%F A221323 Empirical g.f.: x*(1 - x)*(7 - 35*x + 6*x^2 + 8*x^3) / (1 - 23*x + 110*x^2 - 111*x^3 + 6*x^4 + 8*x^5). - _Colin Barker_, Aug 05 2018
%e A221323 Some solutions for n=3:
%e A221323 ..2..1..0....2..2..0....1..1..0....1..1..1....2..1..0....1..0..1....1..0..2
%e A221323 ..2..0..1....0..2..0....2..0..2....0..2..1....1..0..1....1..2..0....2..1..0
%e A221323 ..1..0..2....0..1..2....0..2..1....1..0..2....2..2..0....1..2..1....0..2..1
%Y A221323 Cf. A221328.
%K A221323 nonn
%O A221323 1,1
%A A221323 _R. H. Hardin_, Jan 11 2013