|
%I #8 Nov 26 2018 16:27:14
%S 25,86,310,1135,4172,15353,56519,208082,766105,2820622,10384911,
%T 38234978,140772894,518295264,1908250809,7025765815,25867346793,
%U 95237963740,350645538289,1291000864451,4753185339819,17500198099533,64431935981585
%N Number of (n+1) X (2+1) 0..1 arrays with no 2 X 2 subblock having the minimum of its diagonal elements less than the absolute difference of its antidiagonal elements.
%H R. H. Hardin, <a href="/A251195/b251195.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = 2*a(n-1) + 7*a(n-2) - a(n-3) - 7*a(n-4) - a(n-5) for n>6.
%F Empirical g.f.: x*(25 + 36*x - 37*x^2 - 62*x^3 - 7*x^4 + x^5) / (1 - 2*x - 7*x^2 + x^3 + 7*x^4 + x^5). - _Colin Barker_, Nov 26 2018
%e Some solutions for n=4:
%e ..1..1..1....1..1..1....0..0..1....1..1..1....1..1..1....0..0..1....1..1..1
%e ..1..1..1....1..0..1....0..1..0....1..0..1....1..1..0....0..1..0....1..1..1
%e ..1..1..1....0..1..1....1..0..1....1..1..1....1..1..1....1..0..1....1..1..1
%e ..1..1..1....1..1..1....0..1..1....0..1..1....0..1..1....1..1..1....1..0..1
%e ..1..1..1....1..1..0....1..0..1....1..0..1....1..0..1....1..1..1....0..1..0
%Y Column 2 of A251201.
%K nonn
%O 1,1
%A _R. H. Hardin_, Nov 30 2014
| 