A232509 - OEIS

%I #6 Nov 23 2014 17:18:28

%S 16,52,200,784,3052,11900,46432,181184,707044,2759212,10767816,

%T 42021520,163989692,639972924,2497507216,9746573088,38036202612,

%U 148437067820,579278732344,2260647259184,8822222791628,34428907339516,134359524664384

%N Number of (n+1)X(2+1) 0..2 arrays with every element next to itself plus and minus one within the range 0..2 horizontally, diagonally or antidiagonally, with no adjacent elements equal

%C Column 2 of A232515

%H R. H. Hardin, <a href="/A232509/b232509.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 4*a(n-1) +a(n-2) -4*a(n-3) -5*a(n-4) -2*a(n-5) +a(n-6) +2*a(n-7).

%F Empirical: G.f.: -4*x*(4-3*x-6*x^2-x^3+x^4+x^6) / ( -1+4*x+x^2-4*x^3-5*x^4-2*x^5+x^6+2*x^7 ). - _R. J. Mathar_, Nov 23 2014

%e Some solutions for n=7

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

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

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

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

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

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

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

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

%K nonn

%O 1,1

%A _R. H. Hardin_, Nov 25 2013