login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A229573 Number of defective 4-colorings of an n X 3 0..3 array connected horizontally, vertically, diagonally and antidiagonally with exactly one mistake, and colors introduced in row-major 0..3 order. 1
2, 26, 76, 171, 362, 757, 1584, 3323, 6982, 14673, 30812, 64615, 135282, 282749, 589960, 1228947, 2556062, 5308585, 11010228, 22806719, 47186122, 97517781, 201326816, 415236331, 855638262, 1761607937, 3623878924, 7449084183 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

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

FORMULA

Empirical: a(n) = 6*a(n-1) - 13*a(n-2) + 12*a(n-3) - 4*a(n-4) for n>5.

Empirical g.f.: x*(2 + 14*x - 54*x^2 + 29*x^3 + 20*x^4) / ((1 - x)^2*(1 - 2*x)^2). - Colin Barker, Sep 19 2018

EXAMPLE

Some solutions for n=3:

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

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

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

CROSSREFS

Column 3 of A229578.

Sequence in context: A210848 A247957 A152997 * A067204 A202077 A280212

Adjacent sequences:  A229570 A229571 A229572 * A229574 A229575 A229576

KEYWORD

nonn

AUTHOR

R. H. Hardin, Sep 26 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 | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified September 21 00:17 EDT 2019. Contains 327252 sequences. (Running on oeis4.)