A209907 Half the number of (n+1)X3 0..3 arrays with every 2X2 subblock having two or four distinct clockwise edge differences

562, 13098, 295448, 6711168, 152153160, 3452051294, 78298719958, 1776153151954, 40289004709802, 913904480044196, 20730591242525088, 470244787257936734, 10666837893533545782, 241962270764619764754, 5488573721848784927246

Offset

1,1

Comments

Column 2 of A209913

Links

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

Formula

Empirical: a(n) = 16*a(n-1) +227*a(n-2) -1440*a(n-3) -8244*a(n-4) +46409*a(n-5) +53926*a(n-6) -406100*a(n-7) -117231*a(n-8) +1484559*a(n-9) +166049*a(n-10) -2587430*a(n-11) -386782*a(n-12) +2096907*a(n-13) +472125*a(n-14) -660956*a(n-15) -166954*a(n-16) +44616*a(n-17) +4488*a(n-18) -192*a(n-19)

Example

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

Crossrefs

Sequence in context: A121508 A252344 A250976 * A232679 A135437 A142759

Adjacent sequences: A209904 A209905 A209906 * A209908 A209909 A209910

Keyword

nonn

Author

R. H. Hardin Mar 15 2012

Status

approved