A228686 Number of 5 X n binary arrays with no two ones adjacent horizontally, diagonally or antidiagonally.

32, 99, 1277, 6160, 56549, 333517, 2644336, 17124415, 127116873, 859773376, 6193234393, 42741157353, 303661236672, 2115245880075, 14933039299621, 104468526402928, 735366366459485, 5154677670070421, 36235570461792016

Offset

1,1

Links

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

Formula

Empirical: a(n) = 4*a(n-1) + 34*a(n-2) - 76*a(n-3) - 134*a(n-4) + 258*a(n-5) + 45*a(n-6) - 102*a(n-7).

Empirical g.f.: x*(32 - 29*x - 207*x^2 + 118*x^3 + 303*x^4 - 57*x^5 - 102*x^6) / (1 - 4*x - 34*x^2 + 76*x^3 + 134*x^4 - 258*x^5 - 45*x^6 + 102*x^7). - Colin Barker, Sep 12 2018

Example

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

Crossrefs

Row 5 of A228683.

Sequence in context: A218901 A192293 A188862 * A172517 A194645 A134845

Adjacent sequences: A228683 A228684 A228685 * A228687 A228688 A228689

Keyword

nonn

Author

R. H. Hardin, Aug 30 2013

Status

approved