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!)
A197102 Half the number of n X 1 0..3 arrays with no element equal to the average of its horizontal and vertical neighbors. 1
2, 6, 16, 61, 212, 753, 2661, 9415, 33302, 117802, 416703, 1474018, 5214089, 18443961, 65242401, 230783990, 816359440, 2887733833, 10214871388, 36133384697, 127815754113, 452126672783, 1599321849338, 5657331300590 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 1 of A197109.

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..200

FORMULA

Empirical: a(n) = 2*a(n-1) +5*a(n-2) +3*a(n-3) -4*a(n-4) -4*a(n-5) for n>6.

Empirical g.f.: x*(2 + 2*x - 6*x^2 - 7*x^3 + 8*x^5) / (1 - 2*x - 5*x^2 - 3*x^3 + 4*x^4 + 4*x^5). - Colin Barker, May 11 2018

EXAMPLE

Some solutions for 4 X 4:

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

..1....1....3....3....0....0....3....3....0....0....2....1....3....1....0....2

..1....0....3....2....3....0....3....0....0....1....0....1....0....0....3....0

..0....3....1....0....2....2....2....2....1....0....2....3....1....2....0....1

CROSSREFS

Cf. A197109.

Sequence in context: A027742 A324062 A033301 * A093113 A150030 A150031

Adjacent sequences:  A197099 A197100 A197101 * A197103 A197104 A197105

KEYWORD

nonn

AUTHOR

R. H. Hardin, Oct 10 2011

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 November 30 21:20 EST 2021. Contains 349426 sequences. (Running on oeis4.)