A228657 - OEIS

%I #12 Sep 12 2018 09:08:52

%S 5,38,335,2844,24109,203762,1720343,14516920,122469941,1033083774,

%T 8714026943,73500740436,619954240797,5229079954762,44105207907655,

%U 372009451809136,3137746452123621,26465592072488918,223226285220003247

%N Number of n X 5 binary arrays with top left value 1 and no two ones adjacent horizontally, diagonally or antidiagonally.

%H R. H. Hardin, <a href="/A228657/b228657.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 12*a(n-1) - 27*a(n-2) - 32*a(n-3) + 49*a(n-4) + 20*a(n-5) - 5*a(n-6).

%F Empirical g.f.: x*(5 - 22*x + 14*x^2 + 10*x^3 - 3*x^4) / (1 - 12*x + 27*x^2 + 32*x^3 - 49*x^4 - 20*x^5 + 5*x^6). - _Colin Barker_, Sep 12 2018

%e Some solutions for n=4:

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

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

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

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

%Y Column 5 of A228660.

%K nonn

%O 1,1

%A _R. H. Hardin_, Aug 29 2013