A221110 - OEIS

%I #8 Aug 03 2018 16:28:36

%S 0,7,178,3706,73267,1424745,27551817,531785885,10257442136,

%T 197807790635,3814292012327,73548334004184,1418168141939766,

%U 27345207646288006,527271440369708686,10166866164855156013,196037839679146009768

%N Number of n X 4 arrays of occupancy after each element moves to some horizontal or antidiagonal neighbor, without 2-loops.

%C Column 4 of A221114.

%H R. H. Hardin, <a href="/A221110/b221110.txt">Table of n, a(n) for n = 1..26</a>

%F Empirical: a(n) = 29*a(n-1) - 210*a(n-2) + 451*a(n-3) - 288*a(n-4) + 20*a(n-5) - a(n-6).

%F Empirical g.f.: x^2*(1 - 2*x)*(7 - 11*x - 8*x^2) / ((1 - x)*(1 - 28*x + 182*x^2 - 269*x^3 + 19*x^4 - x^5)). - _Colin Barker_, Aug 03 2018

%e Some solutions for n=3:

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

%e ..0..1..1..0....1..2..3..1....0..2..2..1....0..3..2..0....0..2..3..1

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

%Y Cf. A221114.

%K nonn

%O 1,2

%A _R. H. Hardin_, Jan 02 2013