A205425 Number of (n+1) X 3 0..3 arrays with the number of equal 2 X 2 subblock diagonal pairs and equal antidiagonal pairs differing from each horizontal or vertical neighbor, and new values 0..3 introduced in row major order.

102, 1662, 29022, 513038, 9083342, 160862398, 2848901694, 50454831598, 893569527598, 15825374247326, 280271949540510, 4963697203151822, 87908511615417998, 1556885139957443710, 27572885656837390590

Offset

1,1

Comments

Column 2 of A205431.

Links

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

Formula

Empirical: a(n) = 16*a(n-1) +37*a(n-2) -108*a(n-3) -192*a(n-4).

Empirical g.f.: 2*x*(51 + 15*x - 672*x^2 - 896*x^3) / ((1 - x - 4*x^2)*(1 - 15*x - 48*x^2)). - Colin Barker, Jun 11 2018

Example

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

Crossrefs

Cf. A205431.

Sequence in context: A199830 A200452 A204859 * A206651 A163435 A223308

Adjacent sequences: A205422 A205423 A205424 * A205426 A205427 A205428

Keyword

nonn

Author

R. H. Hardin, Jan 27 2012

Status

approved