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A185409 T(n,k)=1/7 the number of nXk 0..6 arrays with every element equal to exactly one or two of its horizontal and vertical neighbors 5
0, 1, 1, 1, 13, 1, 7, 150, 150, 7, 13, 1848, 5040, 1848, 13, 55, 22656, 279918, 279918, 22656, 55, 133, 278832, 12205368, 53808534, 12205368, 278832, 133, 463, 3430776, 595974240, 9560464068, 9560464068, 595974240, 3430776, 463, 1261, 42221928 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

1,5

COMMENTS

Table starts

....0........1...........1.............7............13............55

....1.......13.........150..........1848.........22656........278832

....1......150........5040........279918......12205368.....595974240

....7.....1848......279918......53808534....9560464068.1755419411964

...13....22656....12205368....9560464068.6409594156632

...55...278832...595974240.1755419411964

..133..3430776.27536905674

..463.42221928

.1261

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..49

EXAMPLE

Some solutions for 4X3 with a(1,1)=0

..0..3..6....0..0..0....0..0..4....0..0..3....0..3..6....0..3..3....0..0..0

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

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

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

CROSSREFS

Column 1 is A015441(n-1)

Sequence in context: A010234 A111738 A202134 * A010235 A196381 A013570

Adjacent sequences:  A185406 A185407 A185408 * A185410 A185411 A185412

KEYWORD

nonn,tabl

AUTHOR

R. H. Hardin Jan 26 2011

STATUS

approved

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Last modified April 21 14:20 EDT 2021. Contains 343154 sequences. (Running on oeis4.)