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A185559 T(n,k)=1/3 the number of nXk 0..2 arrays with every element equal to exactly one or two of its horizontal and vertical neighbors 9
0, 1, 1, 1, 5, 1, 3, 26, 26, 3, 5, 120, 224, 120, 5, 11, 576, 2530, 2530, 576, 11, 21, 2768, 25496, 58458, 25496, 2768, 21, 43, 13256, 269496, 1317540, 1317540, 269496, 13256, 43, 85, 63544, 2792166, 30132444, 64354744, 30132444, 2792166, 63544, 85, 171 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

1,5

COMMENTS

Table starts

...0.......1..........1.............3.................5.................11

...1.......5.........26...........120...............576...............2768

...1......26........224..........2530.............25496.............269496

...3.....120.......2530.........58458...........1317540...........30132444

...5.....576......25496.......1317540..........64354744.........3228500154

..11....2768.....269496......30132444........3228500154.......353403366772

..21...13256....2792166.....684657326......160107914496.....38323943289566

..43...63544...29168100...15594228288.....7976049592892...4170998760222200

..85..304608..303674928..354894362166...396657534279472.453352604882802786

.171.1460072.3165976954.8078976180614.19739291980979494

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..111

EXAMPLE

Some solutions for 5X4 with a(1,1)=0

..0..0..0..0....0..0..0..0....0..0..0..1....0..0..0..1....0..0..0..1

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

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

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

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

CROSSREFS

Column 1 is A001045(n-1)

Sequence in context: A143700 A036790 A201847 * A275842 A147640 A096615

Adjacent sequences:  A185556 A185557 A185558 * A185560 A185561 A185562

KEYWORD

nonn,tabl

AUTHOR

R. H. Hardin Jan 31 2011

STATUS

approved

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Last modified January 27 08:31 EST 2020. Contains 331293 sequences. (Running on oeis4.)