A208376 Number of n X 5 0..1 arrays avoiding 0 0 0 and 1 1 1 horizontally and 0 0 1 and 1 0 1 vertically.

16, 256, 704, 1344, 2176, 3200, 4416, 5824, 7424, 9216, 11200, 13376, 15744, 18304, 21056, 24000, 27136, 30464, 33984, 37696, 41600, 45696, 49984, 54464, 59136, 64000, 69056, 74304, 79744, 85376, 91200, 97216, 103424, 109824, 116416, 123200, 130176

Offset

1,1

Comments

Column 5 of A208379.

Links

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

Formula

Empirical: a(n) = 96*n^2 - 32*n - 64 for n>1.

Conjectures from Colin Barker, Jul 02 2018: (Start)

G.f.: 16*x*(1 + 13*x - x^2 - x^3) / (1 - x)^3.

a(n) = 3*a(n-1) - 3*a(n-2) + a(n-3) for n>4.

(End)

Example

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

Crossrefs

Cf. A208379.

Sequence in context: A206984 A207842 A135554 * A208066 A207931 A207848

Adjacent sequences: A208373 A208374 A208375 * A208377 A208378 A208379

Keyword

nonn

Author

R. H. Hardin, Feb 25 2012

Status

approved