A188868 Number of nX3 binary arrays without the pattern 0 0 0 antidiagonally or horizontally

7, 49, 316, 2032, 13045, 83737, 537496, 3450100, 22145617, 142149013, 912430732, 5856740200, 37593435373, 241305971377, 1548902653984, 9942146967292, 63816977822953, 409630502531629, 2629349654724052, 16877355480293296

Offset

1,1

Comments

Column 3 of A188874

Links

R. H. Hardin, Table of n, a(n) for n = 1..200

Formula

Empirical: a(n) = 7*a(n-1) -3*a(n-2) -5*a(n-3) +2*a(n-4)

Example

Some solutions for 4X3
..0..1..1....1..0..1....0..1..0....1..1..1....1..0..0....0..1..1....0..0..1
..1..0..1....0..1..0....1..1..0....1..0..1....1..1..0....1..1..1....0..1..0
..1..1..0....0..1..1....0..1..1....1..0..0....0..1..0....1..1..1....0..1..1
..1..1..0....0..1..1....1..1..0....1..1..1....1..0..0....0..0..1....1..0..0

Crossrefs

Sequence in context: A133046 A200783 A267230 * A267469 A126639 A268942

Adjacent sequences: A188865 A188866 A188867 * A188869 A188870 A188871

Keyword

nonn

Author

R. H. Hardin Apr 12 2011

Status

approved