A207940 - OEIS

%I #5 Mar 31 2012 12:37:20

%S 8,64,200,643,2422,9430,38207,156792,649758,2703377,11276024,47088326,

%T 196773391,822559178,3439147214,14380613647,60135069834,251472698220,

%U 1051624711847,4397789612658,18391203655144,76910735347923

%N Number of 4Xn 0..1 arrays avoiding 0 0 1 and 1 0 0 horizontally and 0 0 1 and 1 1 0 vertically

%C Row 4 of A207938

%H R. H. Hardin, <a href="/A207940/b207940.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 7*a(n-1) -6*a(n-2) -42*a(n-3) +62*a(n-4) +91*a(n-5) -149*a(n-6) -91*a(n-7) +138*a(n-8) +42*a(n-9) -50*a(n-10) -7*a(n-11) +6*a(n-12) for n>13

%e Some solutions for n=4

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

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

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

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

%K nonn

%O 1,1

%A _R. H. Hardin_ Feb 21 2012