login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A178022 Number of permutations of 4 copies of 1..n with no element e[i>=2]<e[1+floor((i-2)/2)] (2-way heap) 0
1, 7, 206, 18155, 3340366, 1345907216, 965180428296, 1192995518065240 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..8.

CROSSREFS

Simple 2-way heap A056971

Sequence in context: A243144 A234619 A308614 * A157775 A300619 A275822

Adjacent sequences:  A178019 A178020 A178021 * A178023 A178024 A178025

KEYWORD

nonn

AUTHOR

R. H. Hardin May 17 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
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified April 10 11:15 EDT 2021. Contains 342845 sequences. (Running on oeis4.)