login
Number of n X 3 0..1 arrays avoiding 0 0 0 and 0 1 1 horizontally and 0 1 0 and 1 0 1 vertically.
4

%I #7 Jun 18 2022 17:27:19

%S 6,36,98,358,1152,3910,12994,43596,145678,487502,1630196,5453054,

%T 18238998,61008244,204063338,682563198,2283064944,7636504950,

%U 25542956650,85437392020,285775310062,955875582398,3197260259292,10694355621414

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

%C Column 3 of A207467.

%H R. H. Hardin, <a href="/A207462/b207462.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 3*a(n-1) +a(n-2) -4*a(n-3) +11*a(n-4) +15*a(n-5) +4*a(n-6) -23*a(n-7) -17*a(n-8) +4*a(n-9) -7*a(n-10) +a(n-11) +a(n-12).

%e Some solutions for n=4

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

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

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

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

%Y Cf. A207467.

%K nonn

%O 1,1

%A _R. H. Hardin_, Feb 18 2012