A232917 - OEIS

%I #8 Oct 06 2018 05:30:28

%S 48,396,3612,33702,316800,2986152,28178262,266016264,2511769872,

%T 23718269934,223974692940,2115047273040,19973000452170,

%U 188611165560264,1781114471948484,16819628783052894,158833109275938936

%N Number of n X 5 0..2 arrays with no element x(i,j) adjacent to value 2-x(i,j) horizontally, diagonally or antidiagonally.

%H R. H. Hardin, <a href="/A232917/b232917.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 14*a(n-1) - 45*a(n-2) + 15*a(n-3) + 36*a(n-4) - 19*a(n-5) + 2*a(n-6).

%F Empirical g.f.: 6*x*(4 - 7*x + x^2)*(2 - 8*x - 5*x^2 + 3*x^3) / (1 - 14*x + 45*x^2 - 15*x^3 - 36*x^4 + 19*x^5 - 2*x^6). - _Colin Barker_, Oct 06 2018

%e Some solutions for n=4:

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

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

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

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

%Y Column 5 of A232920.

%K nonn

%O 1,1

%A _R. H. Hardin_, Dec 02 2013