A232583 Number of (n+1)X(2+1) 0..2 arrays with every element next to itself plus and minus one within the range 0..2 horizontally or antidiagonally, with no adjacent elements equal

10, 34, 124, 456, 1686, 6232, 23034, 85130, 314626, 1162804, 4297528, 15882942, 58700688, 216947890, 801802986, 2963329250, 10951967500, 40476633544, 149594843398, 552877431048, 2043342182250, 7551849721642, 27910368960066

Offset

1,1

Comments

Column 2 of A232589

Links

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

Formula

Empirical: a(n) = 4*a(n-1) -a(n-2) -a(n-3) +2*a(n-4).

Empirical: G.f.: -2*x*(5-3*x-x^2+2*x^3) / ( -1+4*x-x^2-x^3+2*x^4 ). - R. J. Mathar, Nov 23 2014

Example

Some solutions for n=7
..0..1..2....2..1..2....0..1..2....0..1..2....2..1..2....0..1..0....2..1..0
..0..1..2....0..1..2....2..1..0....0..1..0....0..1..0....2..1..2....2..1..2
..0..1..0....2..1..0....0..1..2....2..1..2....2..1..2....2..1..0....0..1..2
..2..1..2....2..1..0....0..1..2....0..1..2....2..1..0....0..1..0....2..1..2
..0..1..0....0..1..0....2..1..2....2..1..0....2..1..0....2..1..2....0..1..0
..2..1..2....2..1..0....0..1..0....0..1..2....0..1..2....2..1..0....0..1..2
..2..1..2....0..1..2....2..1..0....0..1..0....2..1..0....0..1..2....0..1..2
..0..1..0....0..1..0....2..1..0....2..1..0....2..1..0....0..1..2....0..1..2

Crossrefs

Sequence in context: A119227 A218631 A166066 * A068078 A067806 A001446

Adjacent sequences: A232580 A232581 A232582 * A232584 A232585 A232586

Keyword

nonn

Author

R. H. Hardin, Nov 26 2013

Status

approved