|
%I #9 Nov 27 2018 09:01:12
%S 49,305,1892,11753,72985,453273,2814985,17482154,108570830,674266427,
%T 4187452312,26005680486,161505221644,1003009195172,6229070707553,
%U 38684911434209,240248095245952,1492032555580773,9266092805568853
%N Number of (n+1) X (2+1) 0..1 arrays with no 2 X 2 subblock having the minimum of its diagonal elements greater than the absolute difference of its antidiagonal elements.
%H R. H. Hardin, <a href="/A251222/b251222.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = 5*a(n-1) + 9*a(n-2) - 8*a(n-3) - 8*a(n-4) + 3*a(n-5).
%F Empirical g.f.: x*(49 + 60*x - 74*x^2 - 60*x^3 + 24*x^4) / ((1 - x)*(1 + x)*(1 - 5*x - 8*x^2 + 3*x^3)). - _Colin Barker_, Nov 27 2018
%e Some solutions for n=4:
%e ..0..1..1....0..1..1....1..1..0....1..0..1....0..0..0....1..1..1....0..1..1
%e ..0..0..1....0..1..0....0..0..0....0..0..0....0..0..1....0..0..0....1..0..1
%e ..0..0..0....0..1..1....0..0..0....1..1..1....0..1..1....1..0..1....1..1..0
%e ..0..0..1....1..0..0....0..0..0....0..1..0....0..0..0....0..0..0....0..0..0
%e ..0..0..0....0..0..1....1..1..1....1..1..1....0..0..0....1..0..1....0..0..0
%Y Column 2 of A251228.
%K nonn
%O 1,1
%A _R. H. Hardin_, Nov 30 2014
| 