login
Number of (n+1) X (2+1) 0..2 arrays with the minimum plus the maximum equal to the lower median plus the upper median in every 2 X 2 subblock.
1

%I #12 Oct 20 2018 03:58:13

%S 125,641,3265,17001,89857,482809,2633969,14575785,81703841,463238873,

%T 2652564049,15317772297,89086539265,521188708921,3064017648305,

%U 18084830797161,107087869573217,635770019584409,3782450616803089

%N Number of (n+1) X (2+1) 0..2 arrays with the minimum plus the maximum equal to the lower median plus the upper median in every 2 X 2 subblock.

%H R. H. Hardin, <a href="/A235896/b235896.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 13*a(n-1) - 44*a(n-2) - 24*a(n-3) + 192*a(n-4) + 144*a(n-5).

%F Empirical g.f.: x*(125 - 984*x + 432*x^2 + 5760*x^3 + 3888*x^4) / ((1 - 6*x)*(1 - 4*x - 4*x^2)*(1 - 3*x - 6*x^2)). - _Colin Barker_, Oct 20 2018

%e Some solutions for n=4:

%e ..2..2..0....2..2..1....2..1..1....1..0..1....2..1..0....2..2..2....0..2..1

%e ..1..1..1....1..1..0....1..2..2....1..2..1....0..1..0....0..0..0....2..0..1

%e ..0..0..0....0..2..1....1..2..2....0..1..2....0..1..2....0..0..0....1..1..0

%e ..1..1..1....1..1..2....1..2..2....2..1..2....0..1..0....1..1..1....1..1..0

%e ..2..0..0....1..1..0....1..2..2....2..1..0....1..0..1....2..2..2....2..0..1

%Y Column 2 of A235902.

%K nonn

%O 1,1

%A _R. H. Hardin_, Jan 16 2014