A223382 Number of n X 3 0..2 arrays with all horizontally or vertically connected equal values in a straight line, and new values 0..2 introduced in row major order.

5, 57, 777, 10830, 151962, 2136444, 30053580, 422837280, 5949375984, 83709684792, 1177827765240, 16572513858312, 233182066036872, 3280967627051112, 46164566052169512, 649554466698560040, 9139499021741796072

Offset

1,1

Comments

Column 3 of A223387.

Links

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

Formula

Empirical: a(n) = 19*a(n-1) - 72*a(n-2) + 34*a(n-3) + 44*a(n-4) for n>5.

Empirical g.f.: x*(1 - x)*(5 - 33*x + 21*x^2 + 22*x^3) / (1 - 19*x + 72*x^2 - 34*x^3 - 44*x^4). - Colin Barker, Aug 20 2018

Example

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

Crossrefs

Cf. A223387.

Sequence in context: A322248 A277831 A333091 * A336286 A155539 A285067

Adjacent sequences: A223379 A223380 A223381 * A223383 A223384 A223385

Keyword

nonn

Author

R. H. Hardin, Mar 19 2013

Status

approved