login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A201270 Number of n X n 0..2 arrays with every row and column nondecreasing rightwards and downwards, and the number of instances of each value within one of each other. 0
1, 3, 5, 7, 85, 556, 1260, 27008, 215577, 613916, 16442049, 152673459, 487975060, 14392411292, 144918917509, 496264541787, 15559415313705, 165127072154120, 592098075114238, 19339952787547252, 212870280758956694, 788675446037414831, 26535438036570486429, 300014957716483809886 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,2
LINKS
EXAMPLE
Some solutions for n=5
..0..0..0..0..2....0..0..0..0..2....0..0..0..0..0....0..0..0..0..0
..0..0..1..2..2....0..0..1..1..2....0..0..0..1..1....0..0..1..2..2
..0..1..1..2..2....0..1..1..2..2....1..1..1..1..1....0..1..1..2..2
..0..1..1..2..2....0..1..1..2..2....1..2..2..2..2....1..1..1..2..2
..1..1..1..2..2....1..1..1..2..2....2..2..2..2..2....1..1..1..2..2
CROSSREFS
Main diagonal of A201277.
Sequence in context: A306573 A254925 A153138 * A160360 A082697 A051345
KEYWORD
nonn,changed
AUTHOR
R. H. Hardin, Nov 29 2011
EXTENSIONS
a(0)=1 prepended and a(19)-a(23) added by Alois P. Heinz, Mar 17 2024
STATUS
approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified March 18 22:56 EDT 2024. Contains 370952 sequences. (Running on oeis4.)