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!)
A223720 Number of nX3 0..2 arrays with rows, antidiagonals and columns unimodal 1
22, 484, 5883, 46613, 273562, 1285547, 5087912, 17557701, 54161878, 152154419, 394849354, 957192985, 2187192034, 4745347460, 9834757897, 19568773673, 37541913638, 69694254022, 125590862829, 220277446621, 376922731034 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 3 of A223725

LINKS

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

FORMULA

Empirical: a(n) = (5051/239500800)*n^12 + (61/177408)*n^11 + (91271/21772800)*n^10 + (27/896)*n^9 + (1198121/7257600)*n^8 + (1087/1792)*n^7 + (36617153/21772800)*n^6 + (63719/20160)*n^5 + (26821099/5443200)*n^4 + (305/56)*n^3 + (149993/207900)*n^2 + (3277/770)*n + 1

EXAMPLE

Some solutions for n=3

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

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

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

CROSSREFS

Sequence in context: A207721 A223737 A223635 * A223667 A223826 A223618

Adjacent sequences:  A223717 A223718 A223719 * A223721 A223722 A223723

KEYWORD

nonn

AUTHOR

R. H. Hardin Mar 26 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 November 29 18:41 EST 2021. Contains 349416 sequences. (Running on oeis4.)