A228751 - OEIS

%I #10 Sep 12 2018 15:08:41

%S 5,50,482,4599,43862,418370,3990739,38067290,363121586,3463797759,

%T 33040991486,315176359538,3006451507579,28678390419458,

%U 273561730649282,2609491655262279,24891810279661862,237441732282894050

%N Number of n X 5 binary arrays with top left element equal to 1 and no two ones adjacent horizontally or antidiagonally.

%H R. H. Hardin, <a href="/A228751/b228751.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 13*a(n-1) - 36*a(n-2) + 29*a(n-3) - 5*a(n-4) for n>5.

%F Empirical g.f.: x*(5 - 15*x + 12*x^2 - 12*x^3 + 2*x^4) / ((1 - x)*(1 - 12*x + 24*x^2 - 5*x^3)). - _Colin Barker_, Sep 12 2018

%e Some solutions for n=4:

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

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

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

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

%Y Column 5 of A228754.

%K nonn

%O 1,1

%A _R. H. Hardin_, Sep 02 2013