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!)
A297762 T(n,k)=Number of nXk 0..1 arrays with every 1 horizontally, diagonally or antidiagonally adjacent to 2, 3 or 4 neighboring 1s. 13
1, 1, 1, 1, 2, 1, 1, 12, 4, 1, 1, 31, 52, 7, 1, 1, 78, 206, 186, 14, 1, 1, 225, 734, 1181, 1045, 31, 1, 1, 733, 4088, 7081, 10639, 5685, 69, 1, 1, 2305, 24801, 73352, 109228, 90727, 28565, 155, 1, 1, 7156, 130159, 759243, 2263784, 1456855, 720785, 148681, 354, 1, 1 (list; table; graph; refs; listen; history; text; internal format)
OFFSET
1,5
COMMENTS
Table starts
.1...1......1........1..........1.............1...............1
.1...2.....12.......31.........78...........225.............733
.1...4.....52......206........734..........4088...........24801
.1...7....186.....1181.......7081.........73352..........759243
.1..14...1045....10639.....109228.......2263784........45618455
.1..31...5685....90727....1456855......59707529......2301783905
.1..69..28565...720785...18733087....1504842706....108229776807
.1.155.148681..5909241..251641086...39769163381...5394743533114
.1.354.783104.48847911.3354939709.1043883771677.267870723932943
LINKS
FORMULA
Empirical for column k:
k=1: a(n) = a(n-1)
k=2: a(n) = 3*a(n-1) -2*a(n-2) +2*a(n-3) -2*a(n-4) -a(n-5)
k=3: [order 15]
k=4: [order 33]
k=5: [order 78]
Empirical for row n:
n=1: a(n) = a(n-1)
n=2: a(n) = 4*a(n-1) -3*a(n-2) +a(n-3) +6*a(n-4) -18*a(n-5)
n=3: [order 20]
n=4: [order 52]
EXAMPLE
Some solutions for n=5 k=4
..1..1..1..1. .1..1..1..0. .0..1..1..1. .0..1..1..0. .1..1..1..1
..1..1..1..1. .1..1..1..1. .0..0..1..0. .1..1..1..0. .1..1..1..0
..0..0..0..0. .0..1..0..0. .0..0..1..1. .1..0..0..1. .0..0..0..1
..1..1..1..0. .1..1..1..1. .0..1..1..0. .0..1..1..1. .0..1..1..0
..0..1..1..0. .1..1..1..0. .0..0..0..0. .0..1..1..0. .0..1..1..0
CROSSREFS
Column 2 is A202973.
Sequence in context: A066094 A160625 A324188 * A010246 A186430 A173889
KEYWORD
nonn,tabl
AUTHOR
R. H. Hardin, Jan 05 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 | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified February 21 01:11 EST 2024. Contains 370219 sequences. (Running on oeis4.)