A228681 Number of n X 6 binary arrays with no two ones adjacent horizontally, diagonally or antidiagonally.

21, 217, 2529, 28977, 333517, 3837761, 44171841, 508425617, 5852202757, 67361890809, 775372578689, 8924976046401, 102731553583965, 1182498825731233, 13611237290882689, 156673123529460833, 1803397245448244085

Offset

1,1

Links

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

Formula

Empirical: a(n) = 14*a(n-1) - 17*a(n-2) - 142*a(n-3) + 59*a(n-4) + 352*a(n-5) + 103*a(n-6) - 48*a(n-7).

Empirical g.f.: x*(21 - 77*x - 152*x^2 + 242*x^3 + 407*x^4 + 55*x^5 - 48*x^6) / (1 - 14*x + 17*x^2 + 142*x^3 - 59*x^4 - 352*x^5 - 103*x^6 + 48*x^7). - Colin Barker, Sep 12 2018

Example

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

Crossrefs

Column 6 of A228683.

Sequence in context: A053063 A060933 A075282 * A165223 A152161 A008421

Adjacent sequences: A228678 A228679 A228680 * A228682 A228683 A228684

Keyword

nonn

Author

R. H. Hardin, Aug 30 2013

Status

approved