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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A267960 Number of n X 1 0..2 arrays with every repeated value in every row and column greater than the previous repeated value. 3
3, 9, 24, 63, 159, 394, 957, 2292, 5419, 12678, 29385, 67560, 154215, 349770, 788741, 1769388, 3950499, 8782094, 19445313, 42898032, 94315743, 206709714, 451711869, 984397108, 2139750939, 4639901334, 10038505657, 21672089592, 46693408599 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 1 of A267966.

LINKS

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

FORMULA

Empirical: a(n) = 6*a(n-1) - 9*a(n-2) - 8*a(n-3) + 24*a(n-4) - 16*a(n-6).

Conjectures from Colin Barker, Feb 25 2018: (Start)

G.f.: x*(3 - 9*x - 3*x^2 + 24*x^3 - 3*x^4 - 17*x^5) / ((1 + x)^2*(1 - 2*x)^4).

a(n) = (96*n + 2^n*(9*n*(n*(n+44)+445)+7622) + 640) / 7776 for n even.

a(n) = (2^n*(9*n*(n*(n+44)+445)+7622) - 32*(3*n+20)) / 7776 for n odd.

(End)

EXAMPLE

Some solutions for n=8:

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

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

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

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

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

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

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

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

CROSSREFS

Cf. A267966.

Sequence in context: A267465 A018788 A098690 * A268938 A090400 A123888

Adjacent sequences:  A267957 A267958 A267959 * A267961 A267962 A267963

KEYWORD

nonn

AUTHOR

R. H. Hardin, Jan 22 2016

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 September 17 14:07 EDT 2021. Contains 347478 sequences. (Running on oeis4.)