Voozh

A188987

Number of n X 4 binary arrays without the pattern 0 0 1 antidiagonally or horizontally.

12, 144, 1256, 10812, 92532, 791388, 6768028, 57879084, 494973804, 4232940812, 36199474380, 309572453388, 2647417026444, 22640311889164, 193616539257612, 1655779498747404, 14159977029956108, 121093992068450316

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

COMMENTS

Column 4 of A188992.

LINKS

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

FORMULA

Empirical: a(n) = 9*a(n-1) -36*a(n-3) +24*a(n-4) +36*a(n-5) -48*a(n-6) +16*a(n-7).

Empirical g.f.: 4*x*(1 + x - 2*x^2 + x^3)*(3 + 6*x - 10*x^2 + 4*x^3) / ((1 - x)*(1 - 8*x - 8*x^2 + 28*x^3 + 4*x^4 - 32*x^5 + 16*x^6)). - Colin Barker, May 01 2018

EXAMPLE

Some solutions for 3 X 4:

..1..0..1..1....1..1..0..0....1..0..1..1....1..0..1..1....1..0..1..1

..1..1..1..0....1..1..1..0....1..0..0..0....0..1..0..0....1..1..0..1

..0..1..1..0....0..1..0..1....1..0..0..0....1..1..0..0....1..1..0..1

CROSSREFS

Cf. A188992.

Sequence in context: A189259 A189612 A207183 * A189697 A189059 A189197

Adjacent sequences: A188984 A188985 A188986 * A188988 A188989 A188990

KEYWORD

nonn

AUTHOR

R. H. Hardin, Apr 15 2011

STATUS

approved

URL: https://oeis.org/A188987

⇱ A188987 - OEIS