A210348 1/4 of the number of (n+1) X 2 0..3 arrays with every 2 X 2 subblock having one, two or three distinct clockwise edge differences.

40, 431, 4615, 49484, 530580, 5689274, 61005068, 654148428, 7014344012, 75213872216, 806508362752, 8648082333016, 92732242176864, 994355562040080, 10662343125623728, 114330894613824704, 1225955056113872768

Offset

1,1

Comments

Column 1 of A210355.

Links

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

Formula

Empirical: a(n) = 14*a(n-1) - 30*a(n-2) - 66*a(n-3) + 104*a(n-4) + 136*a(n-5).

Empirical g.f.: x*(5 - 18*x)*(8 + 3*x - 33*x^2 - 30*x^3) / (1 - 14*x + 30*x^2 + 66*x^3 - 104*x^4 - 136*x^5). - Colin Barker, Jul 15 2018

Example

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

Crossrefs

Cf. A210355.

Sequence in context: A247408 A285855 A210355 * A055750 A290611 A115189

Adjacent sequences: A210345 A210346 A210347 * A210349 A210350 A210351

Keyword

nonn

Author

R. H. Hardin, Mar 20 2012

Status

approved