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

 

Logo

Thanks to everyone who made a donation during our annual appeal!
To see the list of donors, or make a donation, see the OEIS Foundation home page.

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A268774 T(n,k)=Number of nXk 0..2 arrays with some element plus some horizontally, vertically, diagonally or antidiagonally adjacent neighbor totalling two exactly once. 8
0, 3, 3, 12, 12, 12, 36, 32, 32, 36, 96, 100, 112, 100, 96, 240, 248, 446, 446, 248, 240, 576, 620, 1524, 2296, 1524, 620, 576, 1344, 1456, 5214, 10340, 10340, 5214, 1456, 1344, 3072, 3380, 17000, 46312, 64112, 46312, 17000, 3380, 3072, 6912, 7656, 54822 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Table starts

....0.....3.....12.......36........96.........240..........576..........1344

....3....12.....32......100.......248.........620.........1456..........3380

...12....32....112......446......1524........5214........17000.........54822

...36...100....446.....2296.....10340.......46312.......198114........837848

...96...248...1524....10340.....64112......387146......2258084......12951796

..240...620...5214....46312....387146.....3104544.....24222418.....185142872

..576..1456..17000...198114...2258084....24222418....255353744....2624246370

.1344..3380..54822...837848..12951796...185142872...2624246370...36091542548

.3072..7656.173244..3472210..73011192..1393319226..26623649020..491176316484

.6912.17148.541910.14245712.406925194.10357051740.266457432340.6585970939900

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..612

FORMULA

Empirical for column k:

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

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

k=3: a(n) = 4*a(n-1) +2*a(n-2) -16*a(n-3) -a(n-4) +12*a(n-5) -4*a(n-6) for n>8

k=4: [order 8] for n>10

k=5: [order 12] for n>14

k=6: [order 16] for n>18

k=7: [order 28] for n>30

EXAMPLE

Some solutions for n=4 k=4

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

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

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

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

CROSSREFS

Column 1 is A167667(n-1).

Sequence in context: A153270 A065957 A303309 * A240801 A032308 A117856

Adjacent sequences:  A268771 A268772 A268773 * A268775 A268776 A268777

KEYWORD

nonn,tabl

AUTHOR

R. H. Hardin, Feb 13 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 January 17 09:54 EST 2020. Contains 330949 sequences. (Running on oeis4.)