A233156 - OEIS

%I #8 Oct 09 2018 14:56:44

%S 27,96,432,1944,8856,40392,184248,840456,3833784,17488008,79772472,

%T 363886344,1659886776,7571661192,34538532408,157549339656,

%U 718669633464,3278249488008,14953908173112,68213041889544,311157393101496

%N Number of 3 X n 0..2 arrays with no element x(i,j) adjacent to value 2-x(i,j) horizontally or antidiagonally.

%H R. H. Hardin, <a href="/A233156/b233156.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 5*a(n-1) - 2*a(n-2) for n>4.

%F Empirical g.f.: 3*x*(9 - 13*x + 2*x^2 - 8*x^3) / (1 - 5*x + 2*x^2). - _Colin Barker_, Oct 09 2018

%e Some solutions for n=5:

%e ..1..0..0..0..1....1..0..1..0..1....0..0..0..1..2....0..1..0..0..1

%e ..0..0..0..0..1....0..0..1..0..1....0..1..2..2..2....0..0..1..0..1

%e ..0..0..1..0..1....1..2..1..0..1....0..1..2..2..2....0..0..0..0..1

%Y Row 3 of A233155.

%K nonn

%O 1,1

%A _R. H. Hardin_, Dec 05 2013