A207237 Number of nX3 0..1 arrays avoiding 0 0 0 and 0 1 1 horizontally and 0 0 1 and 0 1 0 vertically

6, 36, 102, 287, 882, 2491, 6759, 18528, 50244, 134284, 357919, 951428, 2517507, 6644999, 17514496, 46087746, 121122382, 318060011, 834615854, 2188807497, 5737757291, 15035923244, 39391026514, 103174230894, 270192214787

Offset

1,1

Comments

Column 3 of A207242

Links

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

Formula

Empirical: a(n) = 3*a(n-1) -a(n-2) +6*a(n-3) -12*a(n-4) -8*a(n-5) -10*a(n-6) +8*a(n-7) +13*a(n-8) +11*a(n-9) -2*a(n-10) -4*a(n-11) -4*a(n-12) +a(n-14)

Example

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

Crossrefs

Sequence in context: A208023 A207961 A207243 * A207070 A207118 A207704

Adjacent sequences: A207234 A207235 A207236 * A207238 A207239 A207240

Keyword

nonn

Author

R. H. Hardin Feb 16 2012

Status

approved