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!)
A278807 T(n,k)=Number of nXk 0..2 arrays with rows in nondecreasing lexicographic order and columns in nonincreasing lexicographic order. 6
3, 6, 6, 10, 22, 10, 15, 63, 63, 15, 21, 154, 322, 154, 21, 28, 336, 1439, 1439, 336, 28, 36, 672, 5767, 12958, 5767, 672, 36, 45, 1254, 20972, 110455, 110455, 20972, 1254, 45, 55, 2211, 69834, 870473, 2179956, 870473, 69834, 2211, 55, 66, 3718, 214774, 6275546 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Table starts

..3....6......10.........15............21...............28.................36

..6...22......63........154...........336..............672...............1254

.10...63.....322.......1439..........5767............20972..............69834

.15..154....1439......12958........110455...........870473............6275546

.21..336....5767.....110455.......2179956.........41299256..........725674326

.28..672...20972.....870473......41299256.......1976588468........89730161098

.36.1254...69834....6275546.....725674326......89730161098.....10811999412826

.45.2211..214774...41370842...11698232451....3776527762052...1224101415304069

.55.3718..615120..250517485..172994405326..146582077597322.128795068372302728

.66.6006.1653047.1402100369.2356249442222.5255148833158068

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..127

FORMULA

Empirical for column k:

k=1: a(n) = (1/2)*n^2 + (3/2)*n + 1

k=2: [polynomial of degree 6]

k=3: [polynomial of degree 16]

k=4: [polynomial of degree 44]

EXAMPLE

Some solutions for n=4 k=4

..1..0..0..0. .1..0..0..0. .1..1..1..0. .1..1..0..0. .1..1..0..0

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

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

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

CROSSREFS

Diagonal is A229770.

Column 1 is A000217(n+1).

Column 2 is A257200(n+1).

Sequence in context: A147849 A332546 A002853 * A340620 A184137 A135610

Adjacent sequences:  A278804 A278805 A278806 * A278808 A278809 A278810

KEYWORD

nonn,tabl

AUTHOR

R. H. Hardin, Nov 28 2016

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 May 19 15:27 EDT 2022. Contains 353834 sequences. (Running on oeis4.)