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!)
A278676 T(n,k)=Number of nXk 0..1 arrays with rows in nondecreasing lexicographic order and columns in nonincreasing lexicographic order, but with exactly one mistake. 8
0, 1, 1, 4, 8, 4, 10, 33, 33, 10, 20, 99, 158, 99, 20, 35, 245, 579, 579, 245, 35, 56, 532, 1801, 2650, 1801, 532, 56, 84, 1050, 4999, 10584, 10584, 4999, 1050, 84, 120, 1926, 12727, 38848, 55854, 38848, 12727, 1926, 120, 165, 3333, 30218, 134265, 280616 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

1,4

COMMENTS

Table starts

...0....1......4......10........20.........35...........56.............84

...1....8.....33......99.......245........532.........1050...........1926

...4...33....158.....579......1801.......4999........12727..........30218

..10...99....579....2650.....10584......38848.......134265.........441349

..20..245...1801...10584.....55854.....280616......1378241........6654535

..35..532...4999...38848....280616....1998526.....14437336......106388729

..56.1050..12727..134265...1378241...14437336....157706284.....1809189550

..84.1926..30218..441349...6654535..106388729...1809189550....32788533228

.120.3333..67651.1384443..31404174..791018703..21622163723...632621335872

.165.5500.143936.4148373.143558071.5827280865.263667893290.12823358704308

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..219

FORMULA

Empirical for column k:

k=1: a(n) = (1/6)*n^3 - (1/6)*n

k=2: [polynomial of degree 6]

k=3: [polynomial of degree 11]

k=4: [polynomial of degree 20]

k=5: [polynomial of degree 37]

k=6: [polynomial of degree 70]

EXAMPLE

Some solutions for n=4 k=4

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

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

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

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

CROSSREFS

Column 1 is A000292(n-1).

Sequence in context: A141402 A276619 A145900 * A010298 A196177 A059159

Adjacent sequences:  A278673 A278674 A278675 * A278677 A278678 A278679

KEYWORD

nonn,tabl

AUTHOR

R. H. Hardin, Nov 25 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 | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified August 4 09:03 EDT 2020. Contains 336201 sequences. (Running on oeis4.)