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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A189247 Number of n X 2 array permutations with each element making zero or one king moves 2
2, 24, 152, 1168, 8448, 62272, 456320, 3350016, 24579584, 180376576, 1323614208, 9712930816, 71274930176, 523026923520, 3838053810176, 28164247060480, 206673697308672, 1516604287614976, 11129082140426240, 81666965136998400 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 2 of A189254.

LINKS

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

FORMULA

Empirical: a(n) = 6*a(n-1) + 12*a(n-2) - 16*a(n-3).

Empirical g.f.: 2*x*(1 + 6*x - 8*x^2) / (1 - 6*x - 12*x^2 + 16*x^3). - Colin Barker, Mar 01 2018

EXAMPLE

Some solutions for 3 X 2:

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

..0..3....0..4....3..0....5..0....4..2....3..2....3..1....5..1....3..0....3..5

..5..4....5..3....4..5....4..2....3..5....5..4....4..5....4..3....4..5....2..4

CROSSREFS

Cf. A189254.

Sequence in context: A264566 A163752 A035600 * A234352 A241623 A288443

Adjacent sequences:  A189244 A189245 A189246 * A189248 A189249 A189250

KEYWORD

nonn

AUTHOR

R. H. Hardin, Apr 19 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 | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified May 22 18:53 EDT 2019. Contains 323481 sequences. (Running on oeis4.)