A235896 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.

125, 641, 3265, 17001, 89857, 482809, 2633969, 14575785, 81703841, 463238873, 2652564049, 15317772297, 89086539265, 521188708921, 3064017648305, 18084830797161, 107087869573217, 635770019584409, 3782450616803089

Offset

1,1

Links

R. H. Hardin, Table of n, a(n) for n = 1..210

Formula

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

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

Example

Some solutions for n=4:
..2..2..0....2..2..1....2..1..1....1..0..1....2..1..0....2..2..2....0..2..1
..1..1..1....1..1..0....1..2..2....1..2..1....0..1..0....0..0..0....2..0..1
..0..0..0....0..2..1....1..2..2....0..1..2....0..1..2....0..0..0....1..1..0
..1..1..1....1..1..2....1..2..2....2..1..2....0..1..0....1..1..1....1..1..0
..2..0..0....1..1..0....1..2..2....2..1..0....1..0..1....2..2..2....2..0..1

Crossrefs

Column 2 of A235902.

Sequence in context: A070308 A211176 A045170 * A250634 A250944 A251288

Adjacent sequences: A235893 A235894 A235895 * A235897 A235898 A235899

Keyword

nonn

Author

R. H. Hardin, Jan 16 2014

Status

approved