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!)
A231518 Number of nX3 0..1 arrays with no element less than a strict majority of its horizontal, diagonal and antidiagonal neighbors 1
4, 34, 153, 776, 3861, 18721, 91993, 453274, 2223662, 10915727, 53635324, 263420767, 1293604417, 6353594215, 31205396110, 153258629442, 752708346275, 3696838244354, 18156489259107, 89173024237567, 437961215793703 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 3 of A231523

LINKS

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

FORMULA

Empirical: a(n) = 4*a(n-1) -2*a(n-2) +43*a(n-3) -50*a(n-4) +33*a(n-5) -307*a(n-6) +115*a(n-7) -66*a(n-8) +490*a(n-9) +60*a(n-10) -144*a(n-11) +32*a(n-12) -192*a(n-13) for n>14

EXAMPLE

Some solutions for n=7

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

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

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

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

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

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

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

CROSSREFS

Sequence in context: A241231 A297715 A129557 * A196908 A197075 A085695

Adjacent sequences:  A231515 A231516 A231517 * A231519 A231520 A231521

KEYWORD

nonn

AUTHOR

R. H. Hardin, Nov 10 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 4 22:42 EST 2021. Contains 349526 sequences. (Running on oeis4.)