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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
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
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
KEYWORD
nonn,tabl
AUTHOR
R. H. Hardin, Feb 13 2016
STATUS
approved