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

 

Logo

Please make a donation to keep the OEIS running. We are now in our 55th year. In the past year we added 12000 new sequences and reached 8000 citations (which often say "discovered thanks to the OEIS"). We need to raise money to hire someone to manage submissions, which would reduce the load on our editors and speed up editing.
Other ways to donate

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A211364 Inversion sets of finite permutations that have only 0s and 1s in their inversion vectors. 2
0, 1, 4, 3, 32, 33, 20, 11, 512, 513, 516, 515, 288, 289, 148, 75, 16384, 16385, 16388, 16387, 16416, 16417, 16404, 16395, 8704, 8705, 8708, 8707, 4384, 4385, 2196, 1099, 1048576, 1048577, 1048580, 1048579, 1048608, 1048609, 1048596 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

COMMENTS

The finite permutations whose position in reverse colexicographic order is A059590(n) (compare A055089, A195663) have the special feature that their inversion vectors (compare A007623) have only zeros and ones, and give 2*n when interpreted as binary numbers. As the inversion vectors are special, one may also take a look at the inversion sets. This sequence shows them, interpreted as binary numbers (compare A211362).

LINKS

Tilman Piesk, Table of n, a(n) for n = 0..127

FORMULA

a(n) =  A211362(A059590(n))

EXAMPLE

These are the 8 permutations of 4 elements that have only 0s and 1s in their inversion vectors. The left column shows their numbers (compare A055089, A195663), i.e. the beginning of A059590. The right column shows the inversion sets interpreted as binary numbers, i.e. the beginning of this sequence.

No.  permutation  inv. vector  inversion set     a

00     1 2 3 4     0 0 0 0     0  0 0  0 0 0     0

01     2 1 3 4     0 1 0 0     1  0 0  0 0 0     1

02     1 3 2 4     0 0 1 0     0  0 1  0 0 0     4

03     3 1 2 4     0 1 1 0     1  1 0  0 0 0     3

06     1 2 4 3     0 0 0 1     0  0 0  0 0 1    32

07     2 1 4 3     0 1 0 1     1  0 0  0 0 1    33

08     1 4 2 3     0 0 1 1     0  0 1  0 1 0    20

09     4 1 2 3     0 1 1 1     1  1 0  1 0 0    11

CROSSREFS

Cf. A211362, A059590.

Sequence in context: A286795 A127138 A064081 * A099438 A002178 A013558

Adjacent sequences:  A211361 A211362 A211363 * A211365 A211366 A211367

KEYWORD

nonn

AUTHOR

Tilman Piesk, Jun 03 2012

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 December 12 15:11 EST 2019. Contains 329960 sequences. (Running on oeis4.)