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

A229504
Number of defective 3-colorings of an n X 2 0..2 array connected diagonally and antidiagonally with exactly one mistake, and colors introduced in row-major 0..2 order.
1
0, 6, 48, 288, 1536, 7680, 36864, 172032, 786432, 3538944, 15728640, 69206016, 301989888, 1308622848, 5637144576, 24159191040, 103079215104, 438086664192, 1855425871872, 7834020347904, 32985348833280, 138538465099776
OFFSET
1,2
Column 2 of A229510.
FORMULA
Empirical: a(n) = 8*a(n-1) -16*a(n-2).
a(n) = 3/2*(n-1)*4^(n-1) for n = 1..210. - Jérôme Germoni, Sep 18 2015
Empirical g.f.: 6*x^2 / (1 - 4*x)^2. - Colin Barker, Jun 16 2017
EXAMPLE
Some solutions for n=4:
..0..1....0..0....0..1....0..1....0..0....0..1....0..1....0..1....0..1....0..1
..2..0....1..2....1..2....2..2....1..1....2..2....1..1....2..1....0..1....0..1
..2..1....0..0....1..0....2..1....0..1....0..1....0..2....0..1....1..1....2..0
..0..0....0..2....1..2....2..0....2..1....1..1....0..2....1..1....2..2....2..1
CROSSREFS
Sequence in context: A293967 A246587 A340309 * A100740 A043020 A073994
KEYWORD
nonn
AUTHOR
R. H. Hardin, Sep 25 2013
STATUS
approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified September 20 03:37 EDT 2024. Contains 376016 sequences. (Running on oeis4.)