A228752 Number of n X 6 binary arrays with top left element equal to 1 and no two ones adjacent horizontally or antidiagonally.

8, 119, 1712, 24246, 342207, 4823826, 67970044, 957616341, 13491214832, 190066959598, 2677695197199, 37723794440794, 531458704862804, 7487272853619205, 105481862639606840, 1486044856081515654

Offset

1,1

Links

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

Formula

Empirical: a(n) = 21*a(n-1) - 112*a(n-2) + 217*a(n-3) - 157*a(n-4) + 36*a(n-5) for n>6.

Empirical g.f.: x*(8 - 49*x + 109*x^2 - 114*x^3 + 218*x^4 - 78*x^5) / (1 - 21*x + 112*x^2 - 217*x^3 + 157*x^4 - 36*x^5). - Colin Barker, Sep 12 2018

Example

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

Crossrefs

Column 6 of A228754.

Sequence in context: A267752 A318009 A368911 * A360978 A116008 A086302

Adjacent sequences: A228749 A228750 A228751 * A228753 A228754 A228755

Keyword

nonn

Author

R. H. Hardin, Sep 02 2013

Status

approved