A196204 Number of n X 2 0..4 arrays with each element x equal to the number its horizontal and vertical neighbors equal to 2,0,3,4,1 for x=0,1,2,3,4.

3, 5, 8, 11, 18, 28, 43, 67, 105, 164, 257, 404, 636, 1003, 1585, 2509, 3978, 6317, 10046, 15998, 25509, 40723, 65083, 104122, 166737, 267242, 428678, 688151, 1105443, 1776907, 2857894, 4598959, 7404324, 11926298, 19217795, 30978737, 49954191

Offset

1,1

Comments

Every 0 is next to 0 2's, every 1 is next to 1 0's, every 2 is next to 2 3's, every 3 is next to 3 4's, every 4 is next to 4 1's.

Column 2 of A196210.

Links

R. H. Hardin, Table of n, a(n) for n = 1..200

Formula

Empirical: a(n) = 2*a(n-1) - a(n-4) - a(n-5).

Empirical g.f.: x*(1 + x + x^2)*(3 - 4*x - x^2) / ((1 - x - x^2)*(1 - x - x^3)). - Colin Barker, Mar 01 2018

Example

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

Crossrefs

Cf. A196210.

Sequence in context: A320594 A227563 A180619 * A220483 A136684 A215751

Adjacent sequences: A196201 A196202 A196203 * A196205 A196206 A196207

Keyword

nonn

Author

R. H. Hardin, Sep 29 2011

Status

approved