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!)
A198482 Number of 2n X 2 0..3 arrays with values 0..3 introduced in row major order and each element equal to an even number of horizontal and vertical neighbors. 1
5, 193, 10072, 528283, 27711478, 1453628917, 76251331828, 3999827976463, 209814352850962, 11005988987858473, 577328442763429648, 30284250801208664707, 1588585939401430092718, 83330616412779323165533 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 1 of A198485.

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..200

FORMULA

Empirical: a(n) = 55*a(n-1) -135*a(n-2) +81*a(n-3) for n>4.

Empirical g.f.: x*(5 - 82*x + 132*x^2 - 27*x^3) / ((1 - x)*(1 - 54*x + 81*x^2)). - Colin Barker, May 14 2018

EXAMPLE

Some solutions for n=3:

..0..1....0..0....0..1....0..1....0..1....0..1....0..0....0..1....0..1....0..1

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

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

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

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

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

CROSSREFS

Cf. A198485.

Sequence in context: A100760 A240702 A240639 * A198523 A093154 A194572

Adjacent sequences:  A198479 A198480 A198481 * A198483 A198484 A198485

KEYWORD

nonn

AUTHOR

R. H. Hardin, Oct 25 2011

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 August 15 13:59 EDT 2022. Contains 356145 sequences. (Running on oeis4.)