A228751 Number of n X 5 binary arrays with top left element equal to 1 and no two ones adjacent horizontally or antidiagonally.

5, 50, 482, 4599, 43862, 418370, 3990739, 38067290, 363121586, 3463797759, 33040991486, 315176359538, 3006451507579, 28678390419458, 273561730649282, 2609491655262279, 24891810279661862, 237441732282894050

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>5.

Empirical g.f.: x*(5 - 15*x + 12*x^2 - 12*x^3 + 2*x^4) / ((1 - x)*(1 - 12*x + 24*x^2 - 5*x^3)). - Colin Barker, Sep 12 2018

Example

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

Crossrefs

Column 5 of A228754.

Sequence in context: A125962 A361555 A266028 * A299868 A136915 A136918

Adjacent sequences: A228748 A228749 A228750 * A228752 A228753 A228754

Keyword

nonn

Author

R. H. Hardin, Sep 02 2013

Status

approved