A205992 Number of (n+1)X3 0..2 arrays with the number of clockwise edge increases in every 2X2 subblock equal to two, and every 2X2 determinant nonzero

92, 498, 2712, 14866, 81278, 445352, 2436706, 13344256, 73036756, 399888660, 2188990738, 11984113612, 65604360312, 359154388466, 1966148397354, 10763651700178, 58924772138404, 322581389428372, 1765951542920976

Offset

1,1

Comments

Column 2 of A205998

Links

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

Formula

Empirical: a(n) = 3*a(n-1) +17*a(n-2) -19*a(n-3) -4*a(n-4) +27*a(n-5) -13*a(n-6) +8*a(n-8) -4*a(n-9) for n>10

Example

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

Crossrefs

Sequence in context: A100170 A233311 A233309 * A200425 A107343 A355622

Adjacent sequences: A205989 A205990 A205991 * A205993 A205994 A205995

Keyword

nonn

Author

R. H. Hardin Feb 02 2012

Status

approved