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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A230553 Number of involutions avoiding the pattern 1342. 0
1, 1, 2, 4, 10, 24, 62, 156, 406, 1040, 2714, 7012, 18322, 47560, 124358, 323708, 846766, 2208032, 5777330, 15082372, 39469786 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

LINKS

Table of n, a(n) for n=0..20.

Miklós Bóna, Cheyne Homberger, Jay Pantone, and Vince Vatter, Pattern-avoiding involutions: exact and asymptotic enumeration, arxiv:1310.7003, 2013.

EXAMPLE

Of the 26 involutions of length 5, only 14523 and 15342 contain the pattern 1342, so a(5) = 24.

CROSSREFS

Cf. A000085, A001006, A121704, A230551-A230556.

Sequence in context: A006575 A230551 A246566 * A138175 A121691 A124499

Adjacent sequences:  A230550 A230551 A230552 * A230554 A230555 A230556

KEYWORD

nonn

AUTHOR

Cheyne Homberger, Oct 23 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 | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy .

Last modified February 24 11:06 EST 2018. Contains 299603 sequences. (Running on oeis4.)