A253360 - OEIS

%I #8 Dec 11 2018 09:00:05

%S 152,272,560,976,1904,3472,6544,12048,22704,41680,78800,144464,273264,

%T 501008,947472,1737360,3285296,6024272,11391824,20889040,39501296,

%U 72432784,136970896,251161104,474946992,870902224,1646880464,3019856720

%N Number of (n+2) X (1+2) 0..1 arrays with every 2 X 2 and 3 X 3 subblock diagonal maximum minus antidiagonal minimum unequal to its neighbors horizontally and vertically.

%H R. H. Hardin, <a href="/A253360/b253360.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 4*a(n-2) - 3*a(n-4) + 4*a(n-6).

%F Empirical g.f.: 8*x*(19 + 34*x - 6*x^2 - 14*x^3 + 15*x^4 + 48*x^5) / (1 - 4*x^2 + 3*x^4 - 4*x^6). - _Colin Barker_, Dec 11 2018

%e Some solutions for n=4:

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

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

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

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

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

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

%Y Column 1 of A253367.

%K nonn

%O 1,1

%A _R. H. Hardin_, Dec 30 2014