A202594 Number of (n+2) X 3 binary arrays avoiding patterns 001 and 000 in rows and columns.

126, 510, 1968, 7722, 30114, 117708, 459690, 1795842, 7014816, 27402198, 107040102, 418129380, 1633329054, 6380241774, 24923005584, 97356232314, 380300658210, 1485560712012, 5803015490538, 22668201049266, 88548331298112

Offset

1,1

Comments

Column 1 of A202601.

Links

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

Formula

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

Empirical g.f.: 6*x*(21 + 43*x + 11*x^2 - 6*x^3) / (1 - 2*x - 7*x^2 - 2*x^3 + x^4). - Colin Barker, Jun 01 2018

Example

Some solutions for n=3:
..0..1..1....1..0..1....1..1..1....1..0..0....0..1..0....1..1..0....1..1..0
..1..0..0....1..1..1....1..0..1....0..1..1....1..1..1....0..1..1....1..0..1
..0..1..1....0..1..1....1..1..1....1..0..1....0..1..1....1..0..1....1..1..1
..1..1..0....1..1..1....1..1..1....1..1..0....1..0..1....0..1..1....0..1..1
..1..0..0....0..1..1....1..0..1....1..1..1....1..0..1....0..1..0....1..0..0

Crossrefs

Cf. A202601.

Sequence in context: A135192 A154039 A202601 * A245992 A267566 A165023

Adjacent sequences: A202591 A202592 A202593 * A202595 A202596 A202597

Keyword

nonn

Author

R. H. Hardin, Dec 21 2011

Status

approved