A209509 Half the number of (n+1)X7 0..2 arrays with every 2X2 subblock having two or four distinct clockwise edge differences

2187, 53247, 1323270, 33137271, 832374135, 20934997854, 526815563193, 13259938040553, 333783842574072, 8402458085977977, 211521567465170343, 5324833273885068690, 134047481752728606261, 3374518765242613996821

Offset

1,1

Comments

Column 6 of A209511

Links

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

Formula

Empirical: a(n) = 55*a(n-1) -1109*a(n-2) +11330*a(n-3) -67206*a(n-4) +247404*a(n-5) -582440*a(n-6) +881876*a(n-7) -846764*a(n-8) +499200*a(n-9) -172400*a(n-10) +33152*a(n-11) -3264*a(n-12) +128*a(n-13)

Example

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

Crossrefs

Sequence in context: A233160 A269058 A217970 * A016759 A086874 A183810

Adjacent sequences: A209506 A209507 A209508 * A209510 A209511 A209512

Keyword

nonn

Author

R. H. Hardin Mar 09 2012

Status

approved