A206198 Number of (n+1) X (n+1) 0..3 arrays with every 2 X 3 or 3 X 2 subblock having exactly one clockwise edge increases.

256, 1060, 5136, 32920, 118936, 484704, 3270240, 11893600, 48470400, 327024000, 1189360000, 4847040000, 32702400000, 118936000000, 484704000000, 3270240000000, 11893600000000, 48470400000000, 327024000000000

Offset

1,1

Comments

Diagonal of A206206.

Links

Table of n, a(n) for n=1..19.

Formula

Conjectures from Colin Barker, Jan 18 2018: (Start)

G.f.: 4*x*(64 + 265*x + 1284*x^2 + 1830*x^3 + 3234*x^4 - 7224*x^5 - 5440*x^6) / (1 - 100*x^3).

a(n) = 100*a(n-3) for n>7.

(End)

Example

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

Crossrefs

Sequence in context: A045034 A236911 A236904 * A237218 A237212 A237694

Adjacent sequences: A206195 A206196 A206197 * A206199 A206200 A206201

Keyword

nonn

Author

R. H. Hardin Feb 04 2012

Status

approved