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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A190827 Number of permutations of 3 copies of 1..n introduced in order 1..n with no element equal to another within a distance of 2 0
0, 0, 1, 109, 12721, 2001240, 418539642, 113320421342, 38733396860601, 16350175635962731 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,4

LINKS

Table of n, a(n) for n=1..10.

EXAMPLE

Some solutions for n=4

..1....1....1....1....1....1....1....1....1....1....1....1....1....1....1....1

..2....2....2....2....2....2....2....2....2....2....2....2....2....2....2....2

..3....3....3....3....3....3....3....3....3....3....3....3....3....3....3....3

..1....4....4....1....4....4....4....4....4....4....4....1....4....4....4....4

..4....2....1....4....2....1....2....2....2....1....2....4....2....2....1....2

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

..3....3....4....2....3....4....4....1....4....3....1....2....4....3....4....4

..4....2....1....1....4....3....3....4....1....4....4....4....3....4....3....1

..1....4....3....4....1....1....2....3....3....2....2....1....1....1....1....2

..2....1....2....2....2....4....1....2....4....1....3....3....2....2....2....4

..4....3....4....3....4....3....4....4....2....3....1....4....3....3....4....3

..3....4....3....4....3....2....3....1....1....4....4....2....4....4....3....1

CROSSREFS

Sequence in context: A280626 A227949 A144930 * A125044 A096209 A287469

Adjacent sequences:  A190824 A190825 A190826 * A190828 A190829 A190830

KEYWORD

nonn

AUTHOR

R. H. Hardin May 21 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 November 22 08:33 EST 2019. Contains 329389 sequences. (Running on oeis4.)