login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 56th year, we are closing in on 350,000 sequences, and we’ve crossed 9,700 citations (which often say “discovered thanks to the OEIS”).

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A228681 Number of n X 6 binary arrays with no two ones adjacent horizontally, diagonally or antidiagonally. 1
21, 217, 2529, 28977, 333517, 3837761, 44171841, 508425617, 5852202757, 67361890809, 775372578689, 8924976046401, 102731553583965, 1182498825731233, 13611237290882689, 156673123529460833, 1803397245448244085 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

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

FORMULA

Empirical: a(n) = 14*a(n-1) - 17*a(n-2) - 142*a(n-3) + 59*a(n-4) + 352*a(n-5) + 103*a(n-6) - 48*a(n-7).

Empirical g.f.: x*(21 - 77*x - 152*x^2 + 242*x^3 + 407*x^4 + 55*x^5 - 48*x^6) / (1 - 14*x + 17*x^2 + 142*x^3 - 59*x^4 - 352*x^5 - 103*x^6 + 48*x^7). - Colin Barker, Sep 12 2018

EXAMPLE

Some solutions for n=4:

..0..0..0..0..0..0....0..0..0..1..0..0....0..0..0..1..0..0....1..0..1..0..1..0

..1..0..0..1..0..0....0..1..0..1..0..1....0..0..0..0..0..1....0..0..0..0..0..0

..0..0..0..0..0..1....0..0..0..0..0..1....1..0..0..0..0..0....1..0..1..0..0..0

..1..0..0..0..0..0....0..0..0..0..0..1....0..0..1..0..1..0....1..0..0..0..1..0

CROSSREFS

Column 6 of A228683.

Sequence in context: A053063 A060933 A075282 * A165223 A152161 A008421

Adjacent sequences:  A228678 A228679 A228680 * A228682 A228683 A228684

KEYWORD

nonn

AUTHOR

R. H. Hardin, Aug 30 2013

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified December 9 08:41 EST 2021. Contains 349627 sequences. (Running on oeis4.)