A251329 - OEIS

%I #12 Aug 16 2024 18:53:37

%S 171,1115,7393,49937,343299,2399159,17016861,122275189,888413951,

%T 6515113419,48143621385,357960521241,2674701190235,20063864595135,

%U 150970105831061,1138711170122141,8605011245388247,65121221801574931

%N Number of (n+1) X (2+1) 0..2 arrays with every 2 X 2 subblock summing to 2 4 or 6.

%H R. H. Hardin, <a href="/A251329/b251329.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 18*a(n-1) - 98*a(n-2) + 100*a(n-3) + 331*a(n-4) + 42*a(n-5) - 72*a(n-6).

%F Empirical g.f.: x*(171 - 1963*x + 4081*x^2 + 9033*x^3 + 846*x^4 - 1944*x^5) / ((1 + x)*(1 - 6*x)*(1 - 8*x + 3*x^2)*(1 - 5*x - 4*x^2)). - _Colin Barker_, Nov 29 2018

%e Some solutions for n=4:

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

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

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

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

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

%Y Column 2 of A251335.

%K nonn

%O 1,1

%A _R. H. Hardin_, Dec 01 2014