A233628 Number of (n+1) X (1+1) 0..3 arrays with every 2 X 2 subblock having the sum of the absolute values of the edge differences equal to 6.

100, 716, 4974, 34996, 245244, 1721166, 12073496, 84707304, 594267894, 4169203752, 29249652400, 205205717782, 1439652919284, 10100114325196, 70858952369086, 497122227864276, 3487639848551036, 24468090728338830

Offset

1,1

Links

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

Formula

Empirical: a(n) = 5*a(n-1) + 19*a(n-2) - 27*a(n-3) - 55*a(n-4) + 37*a(n-5).

Empirical g.f.: 2*x*(50 + 108*x - 253*x^2 - 389*x^3 + 295*x^4) / (1 - 5*x - 19*x^2 + 27*x^3 + 55*x^4 - 37*x^5). - Colin Barker, Oct 11 2018

Example

Some solutions for n=4:
..1..1....3..2....1..0....1..2....1..3....0..1....3..3....3..3....1..1....0..1
..0..3....2..0....3..0....0..3....1..0....3..3....2..0....0..0....0..3....1..3
..1..3....3..3....3..3....0..3....3..0....0..1....3..2....0..3....1..3....3..2
..3..2....0..0....0..2....2..3....3..0....3..1....1..0....0..1....0..2....1..0
..0..2....0..3....2..3....0..1....3..2....1..2....3..1....0..3....0..3....2..3

Crossrefs

Column 1 of A233635.

Sequence in context: A235850 A264539 A233635 * A030024 A232657 A287027

Adjacent sequences: A233625 A233626 A233627 * A233629 A233630 A233631

Keyword

nonn

Author

R. H. Hardin, Dec 14 2013

Status

approved