A208254 Number of n X 4 0..2 arrays with new values 0..2 introduced in row major order and no element equal to more than one of its immediate leftward or upward neighbors.

14, 768, 43344, 2445264, 137947632, 7782199824, 439026252912, 24767296501776, 1397226183866736, 78823339024454928, 4446752320207192176, 250859789016717819408, 14152043831975777230704, 798375640062491402594064

Offset

1,1

Comments

Column 4 of A208258.

Links

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

Formula

Empirical: a(n) = 61*a(n-1) - 266*a(n-2) + 416*a(n-3) - 256*a(n-4) for n>5.

Empirical g.f.: 2*x*(7 - 43*x + 110*x^2 - 128*x^3 + 64*x^4) / (1 - 61*x + 266*x^2 - 416*x^3 + 256*x^4). - Colin Barker, Jun 29 2018

Example

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

Crossrefs

Cf. A208258.

Sequence in context: A103426 A203750 A232158 * A210817 A042519 A050983

Adjacent sequences: A208251 A208252 A208253 * A208255 A208256 A208257

Keyword

nonn

Author

R. H. Hardin, Feb 24 2012

Status

approved