A206514 Number of (n+1) X 2 0..3 arrays with every 2 X 3 or 3 X 2 subblock having no more than four equal edges, and new values 0..3 introduced in row major order.

15, 186, 2786, 43804, 697369, 11136544, 177977851, 2844864002, 45475406828, 726936444140, 11620303055791, 185754246374086, 2969341279822087, 47465875753570892, 758757303430379258, 12128979771310068836

Offset

1,1

Comments

Column 1 of A206521.

Links

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

Formula

Empirical: a(n) = 18*a(n-1) - 27*a(n-2) - 76*a(n-3) - 111*a(n-4) - 66*a(n-5) - 24*a(n-6) for n>7.

Empirical g.f.: x*(15 - 84*x - 157*x^2 - 182*x^3 - 80*x^4 - 18*x^5 + 8*x^6) / ((1 - 3*x - 3*x^2 - 2*x^3)*(1 - 15*x - 15*x^2 - 12*x^3)). - Colin Barker, Jun 17 2018

Example

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

Crossrefs

Cf. A206521.

Sequence in context: A206521 A366662 A240796 * A016207 A286347 A016147

Adjacent sequences: A206511 A206512 A206513 * A206515 A206516 A206517

Keyword

nonn

Author

R. H. Hardin, Feb 08 2012

Status

approved