A205515 Number of (n+1)X4 0..2 arrays with the number of clockwise edge increases in every 2X2 subblock differing from each horizontal or vertical neighbor

1683, 17166, 205803, 2343348, 27630789, 312856410, 3703472454, 41913844878, 495981580533, 5614380251520, 66435526164984, 752013955358760, 8898757611781614, 100729081045683252, 1191949103431492563

Offset

1,1

Comments

Column 3 of A205520

Links

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

Formula

Empirical: a(n) = 109*a(n-2) +2908*a(n-4) +57127*a(n-6) +121246*a(n-8) +256071*a(n-10) -166046*a(n-12) +879719*a(n-14) -1582201*a(n-16) +1663127*a(n-18) +1566104*a(n-20) -827026*a(n-22) -212087*a(n-24) +1333439*a(n-26) -568096*a(n-28) -811927*a(n-30) +48232*a(n-32) +136964*a(n-34) +17464*a(n-36) -428*a(n-38) +32*a(n-40) for n>41

Example

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

Crossrefs

Sequence in context: A205739 A031719 A206671 * A335338 A263061 A281062

Adjacent sequences: A205512 A205513 A205514 * A205516 A205517 A205518

Keyword

nonn

Author

R. H. Hardin Jan 28 2012

Status

approved