A228794 Number of n X 6 binary arrays with top left element equal to 1 and no two ones adjacent horizontally or nw-se.

8, 98, 1394, 19474, 272952, 3835792, 53992646, 760460212, 10712702564, 150919221210, 2126162067336, 29953658576896, 421991631840838, 5945083016219492, 83755250133013716, 1179956956524018202

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>7.

Empirical g.f.: 2*x*(4 - 35*x + 116*x^2 - 280*x^3 + 58*x^4 - 1256*x^5 + 555*x^6) / (1 - 21*x + 112*x^2 - 217*x^3 + 157*x^4 - 36*x^5). - Colin Barker, Sep 13 2018

Example

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

Crossrefs

Column 6 of A228796.

Sequence in context: A099150 A199029 A228329 * A366035 A211869 A159232

Adjacent sequences: A228791 A228792 A228793 * A228795 A228796 A228797

Keyword

nonn

Author

R. H. Hardin, Sep 04 2013

Status

approved