A208066 Number of n X 5 0..1 arrays avoiding 0 0 0 and 1 1 1 horizontally and 0 0 1 and 0 1 1 vertically.

16, 256, 704, 1936, 3696, 7056, 11424, 18496, 27200, 40000, 55200, 76176, 100464, 132496, 168896, 215296, 267264, 331776, 403200, 490000, 585200, 698896, 822624, 968256, 1125696, 1308736, 1505504, 1731856, 1974000, 2250000, 2544000, 2876416

Offset

1,1

Comments

Column 5 of A208069.

Links

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

Formula

Empirical: a(n) = 2*a(n-1) + 2*a(n-2) - 6*a(n-3) + 6*a(n-5) - 2*a(n-6) - 2*a(n-7) + a(n-8) for n>9.

Empirical g.f.: 16*x*(1 + 14*x + 10*x^2 + 7*x^3 - 3*x^4 - 5*x^5 + 2*x^6 + 2*x^7 - x^8) / ((1 - x)^5*(1 + x)^3). - Colin Barker, Jun 27 2018

Example

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

Crossrefs

Cf. A208069.

Sequence in context: A207842 A135554 A208376 * A207931 A207848 A208837

Adjacent sequences: A208063 A208064 A208065 * A208067 A208068 A208069

Keyword

nonn

Author

R. H. Hardin, Feb 23 2012

Status

approved