A207468 - OEIS

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

%S 10,100,358,1307,4219,11760,33393,88198,229458,590832,1486909,3739145,

%T 9312304,23088739,57148946,140903738,347166896,854103343,2099195971,

%U 5157634036,12663610465,31086972482,76294760274,187208257122

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

%C Row 4 of A207467

%H R. H. Hardin, <a href="/A207468/b207468.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 2*a(n-1) +6*a(n-2) -2*a(n-3) -34*a(n-4) -4*a(n-5) +52*a(n-6) +62*a(n-7) -38*a(n-8) -7*a(n-9) -98*a(n-10) -124*a(n-11) -15*a(n-12) +265*a(n-13) +141*a(n-14) +30*a(n-15) -51*a(n-16) -198*a(n-17) -224*a(n-18) -27*a(n-19) +173*a(n-20) +99*a(n-21) +110*a(n-22) -a(n-23) -38*a(n-24) -84*a(n-25) -9*a(n-26) -17*a(n-27) +12*a(n-28) +8*a(n-29) +13*a(n-30) +2*a(n-32) -a(n-33) -a(n-34) -a(n-35)

%e Some solutions for n=4

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

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

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

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

%K nonn

%O 1,1

%A _R. H. Hardin_ Feb 18 2012