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A269829 T(n,k)=Number of nXk 0..4 arrays with some element plus some horizontally, diagonally, antidiagonally or vertically adjacent neighbor totalling four exactly once. 9
0, 5, 5, 40, 216, 40, 240, 3096, 3096, 240, 1280, 39784, 103296, 39784, 1280, 6400, 462680, 3200604, 3200604, 462680, 6400, 30720, 5145736, 90748696, 240637408, 90748696, 5145736, 30720, 143360, 55265336, 2472983556, 16644595392 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Table starts

......0..........5.............40................240...................1280

......5........216...........3096..............39784.................462680

.....40.......3096.........103296............3200604...............90748696

....240......39784........3200604..........240637408............16644595392

...1280.....462680.......90748696........16644595392..........2840332868960

...6400....5145736.....2472983556......1109236460528........467693538063508

..30720...55265336....65284613232.....71730749075588......74936429415811576

.143360..580002280..1686961414812...4544255355000752...11771832152564634464

.655360.5978552216.42866673833128.283289815771686692.1821445245786662249776

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..144

FORMULA

Empirical for column k:

k=1: a(n) = 8*a(n-1) -16*a(n-2)

k=2: [order 6] for n>7

k=3: [order 18] for n>19

k=4: [order 48] for n>49

EXAMPLE

Some solutions for n=3 k=4

..0..0..3..3. .0..0..2..3. .0..0..2..3. .0..0..0..2. .0..1..4..1

..1..0..2..3. .0..1..3..3. .0..0..2..3. .1..0..1..0. .0..0..1..1

..1..1..3..3. .1..2..4..2. .3..3..3..0. .4..2..1..2. .0..1..2..1

CROSSREFS

Sequence in context: A271289 A271083 A271277 * A270058 A270156 A270164

Adjacent sequences:  A269826 A269827 A269828 * A269830 A269831 A269832

KEYWORD

nonn,tabl

AUTHOR

R. H. Hardin, Mar 05 2016

STATUS

approved

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Last modified July 11 08:10 EDT 2020. Contains 335626 sequences. (Running on oeis4.)