login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 56th year, we are closing in on 350,000 sequences, and we’ve crossed 9,700 citations (which often say “discovered thanks to the OEIS”).

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A283386 T(n,k)=Number of nXk 0..1 arrays with no 1 equal to more than two of its horizontal, vertical and antidiagonal neighbors, with the exception of exactly two elements. 7
0, 0, 0, 0, 1, 0, 0, 3, 3, 0, 0, 19, 60, 19, 0, 0, 91, 532, 532, 91, 0, 0, 399, 4420, 8087, 4420, 399, 0, 0, 1734, 34531, 116624, 116624, 34531, 1734, 0, 0, 7257, 257416, 1592250, 2993934, 1592250, 257416, 7257, 0, 0, 29754, 1862717, 20788531, 71707838 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

1,8

COMMENTS

Table starts

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

.0.....1........3.........19...........91.............399..............1734

.0.....3.......60........532.........4420...........34531............257416

.0....19......532.......8087.......116624.........1592250..........20788531

.0....91.....4420.....116624......2993934........71707838........1644385909

.0...399....34531....1592250.....71707838......3007934404......120672330232

.0..1734...257416...20788531...1644385909....120672330232.....8473366210380

.0..7257..1862717..264040297..36631580212...4702791428260...577497122717510

.0.29754.13180270.3282238215.797807876394.179057922328623.38429377558548084

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..180

FORMULA

Empirical for column k:

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

k=2: [order 24]

k=3: [order 32]

k=4: [order 57] for n>58

EXAMPLE

Some solutions for n=4 k=4

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

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

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

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

CROSSREFS

Sequence in context: A309651 A305541 A280810 * A278385 A245626 A307233

Adjacent sequences:  A283383 A283384 A283385 * A283387 A283388 A283389

KEYWORD

nonn,tabl

AUTHOR

R. H. Hardin, Mar 06 2017

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 30 16:23 EST 2021. Contains 349423 sequences. (Running on oeis4.)