A207108 Number of n X 5 0..1 arrays avoiding 0 0 0 and 0 1 1 horizontally and 0 0 1 and 1 1 0 vertically.

13, 169, 677, 1835, 4047, 7837, 13863, 22931, 36009, 54241, 78961, 111707, 154235, 208533, 276835, 361635, 465701, 592089, 744157, 925579, 1140359, 1392845, 1687743, 2030131, 2425473, 2879633, 3398889, 3989947, 4659955, 5416517, 6267707

Offset

1,1

Comments

Column 5 of A207111.

Links

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

Formula

Empirical: a(n) = (7/60)*n^5 + (8/3)*n^4 + (185/12)*n^3 + (19/3)*n^2 - (218/15)*n + 3.

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

G.f.: x*(13 + 91*x - 142*x^2 + 48*x^3 + 7*x^4 - 3*x^5) / (1 - x)^6.

a(n) = 6*a(n-1) - 15*a(n-2) + 20*a(n-3) - 15*a(n-4) + 6*a(n-5) - a(n-6) for n>6.

(End)

Example

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

Crossrefs

Cf. A207111.

Sequence in context: A208010 A207302 A207915 * A207464 A207239 A208161

Adjacent sequences: A207105 A207106 A207107 * A207109 A207110 A207111

Keyword

nonn

Author

R. H. Hardin, Feb 15 2012

Status

approved