A207043 - OEIS

%I #11 Jun 17 2018 14:40:18

%S 81,150,441,1416,4371,13386,41589,128700,397335,1229310,3802377,

%T 11755344,36352875,112421490,347633853,1075001508,3324303039,

%U 10279835430,31788718257,98301693240,303982182099,940016132634,2906850556773

%N Number of (n+1) X 2 0..2 arrays with every 2 X 3 or 3 X 2 subblock having exactly one clockwise edge increases.

%C Column 1 of A207050.

%H R. H. Hardin, <a href="/A207043/b207043.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 2*a(n-1) + a(n-2) + 8*a(n-3) - 2*a(n-4) for n>5.

%F Empirical g.f.: 3*x*(27 - 4*x + 20*x^2 - 88*x^3 + 20*x^4) / (1 - 2*x - x^2 - 8*x^3 + 2*x^4). - _Colin Barker_, Jun 17 2018

%e Some solutions for n=4:

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

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

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

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

%e   0 0   2 0   0 0   0 0   0 0   0 2   0 0   2 2   2 2   0 0

%Y Cf. A207050.

%K nonn

%O 1,1

%A _R. H. Hardin_, Feb 14 2012