cp's OEIS Frontend

A221922 Number of nX2 arrays of occupancy after each element stays put or moves to some king-move neighbor, without move-in move-out straight through or left turns.

%I A221922 #7 Jul 23 2025 02:19:32
%S A221922 3,35,350,3487,34714,345744,3443699,34300167,341638088,3402798388,
%T A221922 33892698751,337579518956,3362374079673,33490063280467,
%U A221922 333569172221123,3322430051077535,33092211042163927,329606467201422876
%N A221922 Number of nX2 arrays of occupancy after each element stays put or moves to some king-move neighbor, without move-in move-out straight through or left turns.
%C A221922 Column 2 of A221925
%H A221922 R. H. Hardin, <a href="/A221922/b221922.txt">Table of n, a(n) for n = 1..24</a>
%F A221922 Empirical: a(n) = 9*a(n-1) +12*a(n-2) -29*a(n-3) +41*a(n-4) +75*a(n-5) -129*a(n-6) -30*a(n-7) +61*a(n-8) -a(n-9) -4*a(n-10)
%e A221922 Some solutions for n=3
%e A221922 ..0..0....2..2....2..0....1..2....1..0....1..0....1..2....0..0....0..0....1..0
%e A221922 ..3..2....2..0....0..0....1..2....0..4....1..2....1..0....0..3....1..3....3..2
%e A221922 ..0..1....0..0....4..0....0..0....1..0....2..0....2..0....2..1....1..1....0..0
%K A221922 nonn
%O A221922 1,1
%A A221922 _R. H. Hardin_ Jan 31 2013