A208557 - OEIS

A208557

Number of 5 X n 0..1 arrays avoiding 0 0 0 and 0 0 1 horizontally and 0 0 1 and 0 1 1 vertically.

12, 144, 420, 2508, 10080, 50052, 221340, 1042416, 4742628, 21989868, 100900800, 465657348, 2142175548, 9872120016, 45450619620, 209366048652, 964140982560, 4440671206788, 20451041895900, 94190120555184, 433792784654052

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

OFFSET

1,1

COMMENTS

Row 5 of A208555.

LINKS

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

FORMULA

Empirical: a(n) = a(n-1) + 17*a(n-2) + 6*a(n-3) - 36*a(n-4).

Empirical g.f.: 12*x*(1 + 11*x + 6*x^2 - 36*x^3) / ((1 + x - 3*x^2)*(1 - 2*x - 12*x^2)). - Colin Barker, Jul 04 2018

EXAMPLE

Some solutions for n=4:

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

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

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

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

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

CROSSREFS

Cf. A208555.

Sequence in context: A208120 A207370 A208015 * A183355 A267716 A207309

Adjacent sequences: A208554 A208555 A208556 * A208558 A208559 A208560

KEYWORD

nonn

AUTHOR

R. H. Hardin, Feb 28 2012

STATUS

approved