A207264 Number of nX3 0..1 arrays avoiding 0 0 0 and 0 1 1 horizontally and 0 1 1 and 1 0 1 vertically

6, 36, 82, 193, 488, 1087, 2305, 4932, 10416, 21716, 45333, 94798, 198291, 415803, 874740, 1845166, 3902324, 8273999, 17581622, 37429453, 79812519, 170419522, 364296166, 779456642, 1669010171, 3575965948, 7665561753, 16438759769

Offset

1,1

Comments

Column 3 of A207269

Links

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

Formula

Empirical: a(n) = 5*a(n-1) -9*a(n-2) +12*a(n-3) -22*a(n-4) +25*a(n-5) -16*a(n-6) +21*a(n-7) -17*a(n-8) +a(n-9) -6*a(n-10) +6*a(n-11) +a(n-12) +2*a(n-13) -2*a(n-14) for n>15

Example

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

Crossrefs

Sequence in context: A207724 A208689 A207483 * A207270 A207763 A207347

Adjacent sequences: A207261 A207262 A207263 * A207265 A207266 A207267

Keyword

nonn

Author

R. H. Hardin Feb 16 2012

Status

approved