login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A206570 Number of n X 1 0..3 arrays avoiding the pattern z-1 z-1 z in any row, column or nw-to-se diagonal. 4
4, 16, 61, 232, 882, 3353, 12747, 48460, 184229, 700378, 2662606, 10122349, 38481829, 146295209, 556166085, 2114359836, 8038098037, 30558194945, 116172168341, 441648229594, 1679000758004, 6383006556982, 24266083569200 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 1 of A206577.

LINKS

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

FORMULA

Empirical: a(n) = 4*a(n-1) - 3*a(n-3) + 2*a(n-5) - a(n-7).

Empirical g.f.: x*(4 - 3*x^2 + 2*x^4 - x^6) / (1 - 4*x + 3*x^3 - 2*x^5 + x^7). - Colin Barker, Feb 20 2018

EXAMPLE

Some solutions for n=4:

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

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

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

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

CROSSREFS

Cf. A206577.

Sequence in context: A268452 A133161 A103820 * A206790 A283858 A283409

Adjacent sequences:  A206567 A206568 A206569 * A206571 A206572 A206573

KEYWORD

nonn

AUTHOR

R. H. Hardin, Feb 09 2012

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 January 18 06:55 EST 2022. Contains 350454 sequences. (Running on oeis4.)