A207367 - OEIS

%I #5 Mar 31 2012 12:37:17

%S 25,625,3025,14641,45738,142884,353808,876096,1869192,3988009,7660492,

%T 14714896,26130832,46403344,77513748,129481641,205925763,327501409,

%U 500255371,764135449,1128442546,1666435684,2391271116,3431382084

%N Number of nX7 0..1 arrays avoiding 0 0 0 and 0 1 1 horizontally and 0 0 1 and 0 1 1 vertically

%C Column 7 of A207368

%H R. H. Hardin, <a href="/A207367/b207367.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 2*a(n-1) +8*a(n-2) -18*a(n-3) -27*a(n-4) +72*a(n-5) +48*a(n-6) -168*a(n-7) -42*a(n-8) +252*a(n-9) -252*a(n-11) +42*a(n-12) +168*a(n-13) -48*a(n-14) -72*a(n-15) +27*a(n-16) +18*a(n-17) -8*a(n-18) -2*a(n-19) +a(n-20)

%e Some solutions for n=4

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

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

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

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

%K nonn

%O 1,1

%A _R. H. Hardin_ Feb 17 2012