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A269902 T(n,k)=Number of nXk 0..6 arrays with some element plus some horizontally or vertically adjacent neighbor totalling six exactly once. 9
0, 7, 7, 84, 840, 84, 756, 45360, 45360, 756, 6048, 2005080, 12377400, 2005080, 6048, 45360, 80724000, 2801265390, 2801265390, 80724000, 45360, 326592, 3078006120, 579818225700, 3263186052840, 579818225700, 3078006120, 326592, 2286144 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Table starts

.....0..........7..............84.................756.....................6048

.....7........840...........45360.............2005080.................80724000

....84......45360........12377400..........2801265390.............579818225700

...756....2005080......2801265390.......3263186052840.........3482459146452300

..6048...80724000....579818225700....3482459146452300.....19179756370570398120

.45360.3078006120.113873466835170.3529041005211929340.100348236778061082424740

LINKS

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

FORMULA

Empirical for column k:

k=1: a(n) = 12*a(n-1) -36*a(n-2)

k=2: a(n) = 62*a(n-1) -961*a(n-2) for n>3

k=3: a(n) = 330*a(n-1) -28773*a(n-2) +255420*a(n-3) -599076*a(n-4) for n>5

k=4: [order 6] for n>7

k=5: [order 14] for n>15

k=6: [order 26] for n>27

EXAMPLE

Some solutions for n=2 k=4

..2..4..3..2. .3..3..4..4. .3..4..3..6. .5..3..3..0. .2..3..4..5

..0..4..5..2. .0..5..4..0. .0..5..3..1. .0..2..6..4. .0..2..4..3

CROSSREFS

Sequence in context: A274908 A009201 A219353 * A269937 A065240 A178708

Adjacent sequences:  A269899 A269900 A269901 * A269903 A269904 A269905

KEYWORD

nonn,tabl

AUTHOR

R. H. Hardin, Mar 07 2016

STATUS

approved

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Last modified December 9 09:21 EST 2019. Contains 329877 sequences. (Running on oeis4.)