A253439 - OEIS

A253439

Number of (5+1) X (n+1) 0..1 arrays with every 2 X 2 subblock diagonal minus antidiagonal sum nondecreasing horizontally, vertically and ne-to-sw antidiagonally.

%I #7 Dec 12 2018 14:25:05

%S 181,180,193,228,300,444,732,1308,2460,4764,9372,18588,37020,73884,

%T 147612,295068,589980,1179804,2359452,4718748,9437340,18874524,

%U 37748892,75497628,150995100,301990044,603979932,1207959708,2415919260,4831838364

%N Number of (5+1) X (n+1) 0..1 arrays with every 2 X 2 subblock diagonal minus antidiagonal sum nondecreasing horizontally, vertically and ne-to-sw antidiagonally.

%H R. H. Hardin, <a href="/A253439/b253439.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 3*a(n-1) - 2*a(n-2) for n>5.

%F Empirical: a(n) = 9*2^(n-1) + 156 for n>3.

%F Empirical g.f.: x*(181 - 363*x + 15*x^2 + 9*x^3 + 2*x^4) / ((1 - x)*(1 - 2*x)). - _Colin Barker_, Dec 12 2018

%e Some solutions for n=4:

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

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

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

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

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

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

%Y Row 5 of A253435.

%K nonn

%O 1,1

%A _R. H. Hardin_, Dec 31 2014