A207112 - OEIS

%I #5 Mar 31 2012 12:37:15

%S 6,36,98,271,677,1504,3399,7220,15184,31664,64749,132543,268994,

%T 544151,1099824,2215226,4461522,8974915,18040615,36261642,72844037,

%U 146324852,293885650,590165228,1185140667,2379732659,4778367860,9594547523

%N Number of 3Xn 0..1 arrays avoiding 0 0 0 and 0 1 1 horizontally and 0 0 1 and 1 1 0 vertically

%C Row 3 of A207111

%H R. H. Hardin, <a href="/A207112/b207112.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 2*a(n-1) +3*a(n-2) -2*a(n-3) -13*a(n-4) +3*a(n-5) +13*a(n-6) +9*a(n-7) -12*a(n-8) -2*a(n-9) -3*a(n-10) -a(n-11) -2*a(n-12) +8*a(n-13) +a(n-14) -2*a(n-15) -2*a(n-16) +a(n-17)

%e Some solutions for n=4

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

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

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

%K nonn

%O 1,1

%A _R. H. Hardin_ Feb 15 2012