A258550 - OEIS

%I #7 Dec 21 2018 14:22:16

%S 228,344,985,1891,3754,6196,9688,14216,20285,27687,36927,48039,61576,

%T 77378,95998,117518,142539,170949,203349,239869,281158,327152,378500,

%U 435380,498489,567811,644043,727411,818660,917822,1025642,1142394

%N Number of (n+1) X (4+1) 0..1 arrays with every 2 X 2 subblock ne-sw antidiagonal difference nondecreasing horizontally and nw+se diagonal sum nondecreasing vertically.

%H R. H. Hardin, <a href="/A258550/b258550.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 4*a(n-1) - 6*a(n-2) + 4*a(n-3) - 4*a(n-5) + 6*a(n-6) - 4*a(n-7) + a(n-8) for n>12.

%F Empirical g.f.: x*(228 - 568*x + 977*x^2 - 897*x^3 + 724*x^4 - 502*x^5 - 128*x^6 + 412*x^7 - 433*x^8 + 357*x^9 - 136*x^10 + 14*x^11) / ((1 - x)^5*(1 + x)*(1 + x^2)). - _Colin Barker_, Dec 21 2018

%e Some solutions for n=4:

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

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

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

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

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

%Y Column 4 of A258554.

%K nonn

%O 1,1

%A _R. H. Hardin_, Jun 03 2015