|
%I #4 Jan 25 2013 05:23:35
%S 8,240,7371,225873,6916881,211747695,6481445220,198382906386,
%T 6071963365426,185845222595198,5688172415683436,174098004679065547,
%U 5328619769994758026,163093117823302631286,4991792532904719775902
%N Number of nX3 arrays of occupancy after each element stays put or moves to some horizontal or vertical neighbor, without move-in move-out left turns
%C Column 3 of A221773
%H R. H. Hardin, <a href="/A221770/b221770.txt">Table of n, a(n) for n = 1..51</a>
%F Empirical: a(n) = 84*a(n-1) -2905*a(n-2) +56716*a(n-3) -709393*a(n-4) +6061574*a(n-5) -36651293*a(n-6) +159758786*a(n-7) -505601632*a(n-8) +1158517028*a(n-9) -1893716704*a(n-10) +2129563639*a(n-11) -1500050698*a(n-12) +447745570*a(n-13) +217671350*a(n-14) -275450748*a(n-15) +109467496*a(n-16) -17701536*a(n-17) +715760*a(n-18)
%e Some solutions for n=3
%e ..3..1..0....0..3..0....0..1..2....1..0..2....2..2..0....0..2..1....1..0..1
%e ..1..0..2....1..0..0....0..1..1....2..1..0....0..1..1....3..1..0....0..5..0
%e ..0..0..2....3..0..2....1..0..3....0..2..1....0..3..0....1..1..0....1..0..1
%K nonn
%O 1,1
%A _R. H. Hardin_ Jan 25 2013
| 