A204071 Number of (n+1) X 4 0..2 arrays with every 2 X 2 subblock having equal diagonal elements or equal antidiagonal elements, and new values 0..2 introduced in row major order.

188, 2882, 45056, 706454, 11081828, 173848010, 2727300008, 42785526110, 671213931980, 10529919897938, 165192062569424, 2591512360153766, 40655320900906676, 637795575671145050, 10005657004627715960

Offset

1,1

Comments

Column 3 of A204076.

Links

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

Formula

Empirical: a(n) = 20*a(n-1) - 73*a(n-2) + 86*a(n-3) - 32*a(n-4).

Empirical g.f.: 2*x*(94 - 439*x + 570*x^2 - 224*x^3) / ((1 - x)*(1 - 19*x + 54*x^2 - 32*x^3)). - Colin Barker, Jun 06 2018

Example

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

Crossrefs

Cf. A204076.

Sequence in context: A064115 A185241 A211818 * A089273 A035832 A065612

Adjacent sequences: A204068 A204069 A204070 * A204072 A204073 A204074

Keyword

nonn

Author

R. H. Hardin, Jan 10 2012

Status

approved