A207166 Number of n X 5 0..1 arrays avoiding 0 0 0 and 1 0 1 horizontally and 0 0 1 and 1 0 1 vertically.

13, 169, 624, 1612, 3445, 6513, 11284, 18304, 28197, 41665, 59488, 82524, 111709, 148057, 192660, 246688, 311389, 388089, 478192, 583180, 704613, 844129, 1003444, 1184352, 1388725, 1618513, 1875744, 2162524, 2481037, 2833545, 3222388, 3649984

Offset

1,1

Comments

Column 5 of A207169.

Links

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

Formula

Empirical: a(n) = (13/4)*n^4 + (13/2)*n^3 + (117/4)*n^2 - 26*n.

Conjectures from Colin Barker, Jun 19 2018: (Start)

G.f.: 13*x*(1 + 8*x - 7*x^2 + 4*x^3) / (1 - x)^5.

a(n) = 5*a(n-1) - 10*a(n-2) + 10*a(n-3) - 5*a(n-4) + a(n-5) for n>5.

(End)

Example

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

Crossrefs

Cf. A207169.

Sequence in context: A208422 A207787 A207021 * A207365 A208010 A207302

Adjacent sequences: A207163 A207164 A207165 * A207167 A207168 A207169

Keyword

nonn

Author

R. H. Hardin, Feb 15 2012

Status

approved