A263334 Number of (n+2) X (1+2) 0..2 arrays with each row and column divisible by 13, read as a base-3 number with top and left being the most significant digits.

3, 7, 19, 57, 169, 505, 1515, 4543, 13627, 40881, 122641, 367921, 1103763, 3311287, 9933859, 29801577, 89404729, 268214185, 804642555, 2413927663, 7241782987, 21725348961, 65176046881, 195528140641, 586584421923, 1759753265767

Offset

1,1

Links

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

Formula

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

Empirical g.f.: x*(3 - 2*x - 2*x^2 - 3*x^3) / ((1 - x)*(1 - 3*x)*(1 + x + x^2)). - Colin Barker, Jan 01 2019

Example

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

Crossrefs

Column 1 of A263337.

Sequence in context: A306088 A188625 A258171 * A005506 A268125 A287484

Adjacent sequences: A263331 A263332 A263333 * A263335 A263336 A263337

Keyword

nonn

Author

R. H. Hardin, Oct 15 2015

Status

approved