A204279 Number of (n+2) X 5 0..2 arrays with every 3 X 3 subblock having three equal elements in a row horizontally, vertically, diagonally or antidiagonally exactly three ways, and new values 0..2 introduced in row major order.

783, 865, 128, 256, 334, 778, 1990, 4758, 12782, 34702, 93502, 255070, 696478, 1900254, 5190878, 14181022, 38738206, 105833374, 289140766, 789937182, 2158145822, 5896161310, 16108592158, 44009486878, 120236148766, 328491227166

Offset

1,1

Comments

Column 3 of A204284.

Links

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

Formula

Empirical: a(n) = 3*a(n-1) -6*a(n-4) +4*a(n-6) for n>8.

Empirical g.f.: x*(783 - 1484*x - 2467*x^2 - 128*x^3 + 4264*x^4 + 4966*x^5 - 2708*x^6 - 3136*x^7) / ((1 - x)*(1 - 2*x - 2*x^2)*(1 - 2*x^3)). - Colin Barker, Jun 06 2018

Example

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

Crossrefs

Cf. A204284.

Sequence in context: A003914 A238925 A045074 * A158399 A007243 A146978

Adjacent sequences: A204276 A204277 A204278 * A204280 A204281 A204282

Keyword

nonn

Author

R. H. Hardin, Jan 13 2012

Status

approved