%I #8 Mar 14 2018 07:16:48
%S 1,31,318,3605,39851,441912,4896043,54248371,601050906,6659404865,
%T 73783381595,817488259440,9057417947527,100352286120727,
%U 1111860046543146,12318929680916909,136488426454208783,1512232882805726640
%N Number of n X 2 arrays of occupancy after each element moves to some king-move neighbor.
%C Column 2 of A221192.
%H R. H. Hardin, <a href="/A221189/b221189.txt">Table of n, a(n) for n = 1..20</a>
%F Empirical: a(n) = 15*a(n-1) - 41*a(n-2) - 42*a(n-3) + 174*a(n-4) - 86*a(n-5) - 2*a(n-6).
%F Empirical g.f.: x*(1 + 16*x - 106*x^2 + 148*x^3 - 58*x^4) / (1 - 15*x + 41*x^2 + 42*x^3 - 174*x^4 + 86*x^5 + 2*x^6). - _Colin Barker_, Mar 14 2018
%e Some solutions for n=3:
%e ..0..0....0..2....1..1....2..2....0..0....1..0....0..0....0..2....0..1....2..0
%e ..1..3....0..1....0..1....0..1....1..1....1..2....2..0....2..1....4..0....2..0
%e ..1..1....2..1....3..0....0..1....2..2....1..1....1..3....1..0....0..1....0..2
%Y Cf. A221192.
%K nonn
%O 1,2
%A _R. H. Hardin_, Jan 04 2013