A223056 Number of n X 2 0..3 arrays with all horizontally or vertically connected equal values in a straight line, and new values 0..3 introduced in row major order.

2, 10, 114, 1473, 19360, 255045, 3361024, 44294253, 583749160, 7693175205, 101387647984, 1336178514333, 17609374162360, 232072328089365, 3058459941439744, 40307163247443213, 531204410117077960

Offset

1,1

Comments

Column 2 of A223062.

Links

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

Formula

Empirical: a(n) = 18*a(n-1) - 71*a(n-2) + 102*a(n-3) - 48*a(n-4) for n>5.

Empirical g.f.: x*(2 - 26*x + 76*x^2 - 73*x^3 + 16*x^4) / ((1 - x)*(1 - 2*x)*(1 - 15*x + 24*x^2)). - Colin Barker, Aug 16 2018

Example

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

Crossrefs

Cf. A223062.

Sequence in context: A363206 A317342 A226300 * A208782 A237749 A113089

Adjacent sequences: A223053 A223054 A223055 * A223057 A223058 A223059

Keyword

nonn

Author

R. H. Hardin, Mar 13 2013

Status

approved