|
%I #5 Mar 31 2012 12:37:00
%S 0,4,132,256,5260,37636,321696,2951524,26486820,229461904,2051332140,
%T 18106931844,160285145184,1419610292676,12571883432500,
%U 111281907352576,985420995488860,8724655803209956,77248992679400736,683971842578913604
%N Number of nX3 0..3 arrays with every element neighboring horizontally or vertically both a 0 and a 1
%C Column 3 of A204084
%H R. H. Hardin, <a href="/A204079/b204079.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = 9*a(n-1) -3*a(n-3) -53*a(n-4) -204*a(n-5) +6138*a(n-6) -54492*a(n-7) +9384*a(n-8) -51288*a(n-9) +466488*a(n-10) -62016*a(n-11) -306128*a(n-12) +3916128*a(n-13) +2633856*a(n-15) -33362176*a(n-16) for n>19
%e Some solutions for n=5
%e ..3..0..0....1..0..0....2..0..0....0..0..2....3..0..0....0..0..1....1..0..3
%e ..1..1..1....1..0..1....1..1..1....1..1..1....1..1..1....1..1..1....1..0..1
%e ..0..1..0....1..2..1....0..1..3....3..3..0....0..3..0....0..3..0....0..0..1
%e ..0..0..0....0..1..0....0..1..0....0..0..0....0..0..0....0..0..0....0..1..0
%e ..1..1..1....0..1..0....0..1..0....1..1..1....1..1..1....1..1..1....3..1..0
%K nonn
%O 1,2
%A _R. H. Hardin_ Jan 10 2012
| 