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

 

Logo

The October issue of the Notices of the Amer. Math. Soc. has an article about the OEIS.

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A177584 Number of permutations of 2 copies of 1..n avoiding adjacent step pattern up, down, up, down, up, down 0
1, 6, 90, 2350, 99652, 6149364, 520470852, 58016022928, 8228785850728, 1447745572453056 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

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

CROSSREFS

Sequence in context: A001499 A147630 A221097 * A177558 A177580 A177587

Adjacent sequences:  A177581 A177582 A177583 * A177585 A177586 A177587

KEYWORD

nonn

AUTHOR

R. H. Hardin May 10 2010

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 September 25 01:17 EDT 2018. Contains 315360 sequences. (Running on oeis4.)