A234762 Number of (n+1) X (1+1) 0..3 arrays with 2 X 2 edge jumps all no more than +1 in one of the clockwise or counterclockwise directions but not both.

56, 240, 916, 3800, 14828, 60552, 239044, 967784, 3845148, 15493000, 61775668, 248247480, 991807292, 3979719864, 15917452772, 63817779896, 255404741740, 1023525137992, 4097640224516, 16416968389544, 65737110052316

Offset

1,1

Links

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

Formula

Empirical: a(n) = a(n-1) + 14*a(n-2) - a(n-3) - 25*a(n-4) - 10*a(n-5).

Empirical g.f.: 4*x*(14 + 46*x - 27*x^2 - 105*x^3 - 39*x^4) / (1 - x - 14*x^2 + x^3 + 25*x^4 + 10*x^5). - Colin Barker, Oct 16 2018

Example

Some solutions for n=5:
..0..0....1..1....1..2....3..0....1..2....1..2....2..2....2..1....2..3....3..2
..2..1....0..2....0..2....2..1....3..2....1..3....1..0....2..3....1..1....0..1
..2..3....1..2....1..1....3..3....1..2....1..2....1..2....2..1....0..2....2..2
..2..1....0..2....2..3....1..2....0..0....0..0....1..3....0..0....1..2....1..0
..3..1....1..2....1..1....0..3....1..2....2..1....1..2....2..1....3..2....1..2
..3..2....0..0....3..2....1..2....0..3....2..3....1..3....0..1....1..1....1..0

Crossrefs

Column 1 of A234769.

Sequence in context: A233989 A233982 A234769 * A239597 A259039 A158487

Adjacent sequences: A234759 A234760 A234761 * A234763 A234764 A234765

Keyword

nonn

Author

R. H. Hardin, Dec 30 2013

Status

approved