A228793 Number of n X 5 binary arrays with top left element equal to 1 and no two ones adjacent horizontally or nw-se.

5, 42, 411, 3957, 37944, 362511, 3459357, 33001836, 314810115, 3002974197, 28645256880, 273245752503, 2606477735997, 24863061056388, 237167495775339, 2262328872630837, 21580241878243944, 205852847074664031

Offset

1,1

Links

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

Formula

Empirical: a(n) = 13*a(n-1) - 36*a(n-2) + 29*a(n-3) - 5*a(n-4) for n>6.

Empirical g.f.: x*(5 - 23*x + 45*x^2 - 19*x^3 + 106*x^4 - 18*x^5) / ((1 - x)*(1 - 12*x + 24*x^2 - 5*x^3)). - Colin Barker, Sep 13 2018

Example

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

Crossrefs

Column 5 of A228796.

Sequence in context: A215785 A082145 A126765 * A330628 A327272 A024492

Adjacent sequences: A228790 A228791 A228792 * A228794 A228795 A228796

Keyword

nonn

Author

R. H. Hardin, Sep 04 2013

Status

approved