A206005 Number of (n+1)X4 0..2 arrays with the number of clockwise edge increases in every 2X2 subblock equal to one, and every 2X2 determinant nonzero

228, 980, 2728, 12068, 33572, 150396, 419108, 1895206, 5286788, 24077032, 67200552, 307662788, 858930264, 3947689488, 11022344624, 50802408116, 141850386688, 655129480632, 1829250701552, 8460734276112, 23623691166880

Offset

1,1

Comments

Column 3 of A206010

Links

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

Formula

Empirical: a(n) = 32*a(n-2) -356*a(n-4) +1590*a(n-6) -2264*a(n-8) -8*a(n-10) +1168*a(n-12) -336*a(n-14) for n>18

Example

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

Crossrefs

Sequence in context: A043411 A172531 A258557 * A228963 A252220 A263301

Adjacent sequences: A206002 A206003 A206004 * A206006 A206007 A206008

Keyword

nonn

Author

R. H. Hardin Feb 02 2012

Status

approved