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!)
A281605 T(n,k)=Number of nXk 0..2 arrays with no element equal to more than one of its horizontal, diagonal or antidiagonal neighbors and with new values introduced in order 0 sequentially upwards. 11
1, 2, 2, 4, 9, 5, 11, 29, 50, 14, 30, 110, 209, 285, 41, 82, 442, 1283, 1623, 1617, 122, 224, 1708, 8180, 16198, 12413, 9188, 365, 612, 6596, 49572, 167545, 203276, 95623, 52193, 1094, 1672, 25624, 302304, 1626073, 3401430, 2563481, 736757, 296511, 3281, 4568 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Table starts

....1.......2.........4..........11.............30.............82

....2.......9........29.........110............442...........1708

....5......50.......209........1283...........8180..........49572

...14.....285......1623.......16198.........167545........1626073

...41....1617.....12413......203276........3401430.......52899445

..122....9188.....95623.....2563481.......69506779.....1732267694

..365...52193....736757....32354824.....1421127262....56764280423

.1094..296511...5678559...408458506....29066686772..1860912910152

.3281.1684466..43771933..5156857179...594539026170.61012156448915

.9842.9569425.337417047.65107404580.12161158312943

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..112

FORMULA

Empirical for column k:

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

k=2: a(n) = 6*a(n-1) -11*a(n-3) +4*a(n-4) for n>5

k=3: a(n) = 7*a(n-1) +10*a(n-2) -26*a(n-3) -64*a(n-4) -40*a(n-5) for n>6

k=4: [order 16] for n>18

k=5: [order 40] for n>42

Empirical for row n:

n=1: a(n) = 2*a(n-1) +2*a(n-2) for n>4

n=2: a(n) = 4*a(n-1) -2*a(n-2) +8*a(n-3) -8*a(n-4) for n>5

n=3: [order 13] for n>15

n=4: [order 55] for n>58

EXAMPLE

Some solutions for n=4 k=4

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

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

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

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

CROSSREFS

Column 1 is A007051(n-1).

Column 2 is A231413(n-1).

Row 1 is A021006(n-3).

Row 2 is A280853.

Sequence in context: A241130 A019822 A322765 * A199499 A160126 A257515

Adjacent sequences:  A281602 A281603 A281604 * A281606 A281607 A281608

KEYWORD

nonn,tabl

AUTHOR

R. H. Hardin, Jan 25 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 October 15 18:54 EDT 2021. Contains 348034 sequences. (Running on oeis4.)