login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A317871 T(n,k)=Number of nXk 0..1 arrays with every element unequal to 2, 3 or 5 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero. 7
0, 0, 0, 0, 1, 0, 0, 1, 1, 0, 0, 2, 1, 2, 0, 0, 4, 6, 6, 4, 0, 0, 9, 4, 26, 4, 9, 0, 0, 22, 5, 88, 88, 5, 22, 0, 0, 53, 10, 301, 220, 301, 10, 53, 0, 0, 130, 36, 1089, 759, 759, 1089, 36, 130, 0, 0, 320, 34, 4340, 3303, 4692, 3303, 4340, 34, 320, 0, 0, 788, 43, 16696, 11807, 27620 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

1,12

COMMENTS

Table starts

.0...0..0.....0.....0......0.......0.........0..........0...........0

.0...1..1.....2.....4......9......22........53........130.........320

.0...1..1.....6.....4......5......10........36.........34..........43

.0...2..6....26....88....301....1089......4340......16696.......64514

.0...4..4....88...220....759....3303.....11807......45995......161983

.0...9..5...301...759...4692...27620....167100.....990871.....5767582

.0..22.10..1089..3303..27620..163297...1242087....7872632....53760082

.0..53.36..4340.11807.167100.1242087..13125877..113996501..1068543427

.0.130.34.16696.45995.990871.7872632.113996501.1146051177.13578301848

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..220

FORMULA

Empirical for column k:

k=1: a(n) = a(n-1)

k=2: a(n) = 2*a(n-1) +a(n-2) +a(n-3) -a(n-4) -a(n-5) -a(n-6)

k=3: [order 18]

k=4: [order 83] for n>86

EXAMPLE

Some solutions for n=5 k=4

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

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

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

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

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

CROSSREFS

Column 2 is A317735.

Sequence in context: A241291 A317741 A317902 * A082995 A079549 A143374

Adjacent sequences:  A317868 A317869 A317870 * A317872 A317873 A317874

KEYWORD

nonn,tabl

AUTHOR

R. H. Hardin, Aug 09 2018

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 April 25 16:08 EDT 2019. Contains 322461 sequences. (Running on oeis4.)