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!)
A229536 Number of defective 3-colorings of a 3 X n 0..2 array connected horizontally, diagonally and antidiagonally with exactly one mistake, and colors introduced in row-major 0..2 order. 1
0, 20, 58, 361, 1588, 7460, 33136, 146300, 634976, 2729872, 11628320, 49175856, 206658752, 863838624, 3594073792, 14892589280, 61487645824, 253053701600, 1038460551744, 4250534994848, 17357200322560, 70727788661344 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
LINKS
FORMULA
Empirical: a(n) = 6*a(n-1) - a(n-2) - 28*a(n-3) - 4*a(n-4) + 16*a(n-5) - 4*a(n-6) for n>8.
Empirical g.f.: x^2*(20 - 62*x + 33*x^2 + 40*x^3 - 3*x^4 - 16*x^5 + 4*x^6) / (1 - 3*x - 4*x^2 + 2*x^3)^2. - Colin Barker, Sep 18 2018
EXAMPLE
Some solutions for n=4:
..0..1..0..1....0..1..0..2....0..1..2..1....0..1..2..1....0..1..2..1
..0..2..0..2....0..2..1..2....0..1..0..1....0..1..2..1....2..0..2..1
..2..1..0..1....0..2..0..2....2..2..0..1....2..0..2..0....2..0..2..1
CROSSREFS
Row 3 of A229534.
Sequence in context: A069132 A124713 A126374 * A220013 A220046 A275167
KEYWORD
nonn
AUTHOR
R. H. Hardin, Sep 25 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 | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified March 28 18:04 EDT 2024. Contains 371254 sequences. (Running on oeis4.)