A196072 Number of n X 2 0..4 arrays with each element x equal to the number its horizontal and vertical neighbors equal to 0,3,2,1,4 for x=0,1,2,3,4.

0, 1, 2, 0, 6, 2, 8, 12, 10, 32, 26, 58, 82, 104, 204, 238, 424, 606, 870, 1438, 1952, 3156, 4602, 6848, 10634, 15354, 23794, 35192, 52844, 80254, 118744, 180686, 269382, 405118, 610576, 911988, 1377066, 2061328, 3099290, 4659546, 6984594, 10512968

Offset

1,3

Comments

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

Column 2 of A196078.

Links

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

Formula

Empirical: a(n) = a(n-2) +a(n-3) +2*a(n-5).

Empirical g.f.: x^2*(1 + 2*x - x^2 + 3*x^3) / (1 - x^2 - x^3 - 2*x^5). - Colin Barker, May 08 2018

Example

All solutions for n=5:
..2..2....2..2....1..0....1..0....0..1....0..1
..2..2....2..2....3..1....3..1....1..3....1..3
..0..1....1..0....1..1....1..0....0..1....1..1
..1..3....3..1....1..3....2..2....2..2....3..1
..0..1....1..0....0..1....2..2....2..2....1..0

Crossrefs

Cf. A196078.

Sequence in context: A346790 A217572 A021833 * A261883 A294779 A049257

Adjacent sequences: A196069 A196070 A196071 * A196073 A196074 A196075

Keyword

nonn

Author

R. H. Hardin, Sep 27 2011

Status

approved