A253433 - OEIS

A253433

Number of (n+1) X (6+1) 0..1 arrays with every 2 X 2 subblock diagonal minus antidiagonal sum nondecreasing horizontally, vertically and ne-to-sw antidiagonally.

%I #8 Dec 12 2018 09:40:44

%S 325,318,336,372,444,588,876,1452,2604,4908,9516,18732,37164,74028,

%T 147756,295212,590124,1179948,2359596,4718892,9437484,18874668,

%U 37749036,75497772,150995244,301990188,603980076,1207959852,2415919404,4831838508

%N Number of (n+1) X (6+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="/A253433/b253433.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>3.

%F Empirical: a(n) = 9*2^(n-1) + 300 for n>1.

%F Empirical g.f.: x*(325 - 657*x + 32*x^2) / ((1 - x)*(1 - 2*x)). - _Colin Barker_, Dec 12 2018

%e Some solutions for n=4:

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

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

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

%Y Column 6 of A253435.

%K nonn

%O 1,1

%A _R. H. Hardin_, Dec 31 2014