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

 

Logo

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 56th year, we are closing in on 350,000 sequences, and we’ve crossed 9,700 citations (which often say “discovered thanks to the OEIS”).

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A223581 Number of nX4 0..3 arrays with antidiagonals unimodal 1
256, 65536, 10240000, 1331200000, 173056000000, 22497280000000, 2924646400000000, 380204032000000000, 49426524160000000000, 6425448140800000000000, 835308258304000000000000 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 4 of A223585

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..210

FORMULA

Let U(z) = (z^6+15*z^5+115*z^4+405*z^3+964*z^2+660*z+720)/720

a(n) = U(min(n,4))^(max(n,4)-min(n,4)+1) * product{ U(i)^2 , i=1..(min(n,4)-1) }

a(n) = 130*a(n-1) for n>3

EXAMPLE

Some solutions for n=3

..0..0..2..1....0..0..3..0....0..2..2..1....0..0..2..0....0..0..0..2

..0..1..3..1....0..3..2..1....0..0..1..2....0..2..1..1....0..3..3..3

..1..2..3..3....1..1..3..1....0..1..1..1....0..3..0..1....1..2..0..3

CROSSREFS

Sequence in context: A188909 A189110 A223803 * A133752 A144322 A223266

Adjacent sequences:  A223578 A223579 A223580 * A223582 A223583 A223584

KEYWORD

nonn

AUTHOR

R. H. Hardin Mar 22 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
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified December 3 08:56 EST 2021. Contains 349445 sequences. (Running on oeis4.)