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A201847 T(n,k)=Number of zero-sum nXk -1..1 arrays with every element equal to at least one horizontal or vertical neighbor 9
0, 1, 1, 1, 5, 1, 3, 25, 25, 3, 1, 97, 125, 97, 1, 9, 411, 2019, 2019, 411, 9, 7, 1897, 17031, 54773, 17031, 1897, 7, 25, 8741, 259811, 1566319, 1566319, 259811, 8741, 25, 25, 41689, 2809217, 47249907, 109797321, 47249907, 2809217, 41689, 25, 83, 201985 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

1,5

COMMENTS

Table starts

..0......1..........1.............3..............1...............9

..1......5.........25............97............411............1897

..1.....25........125..........2019..........17031..........259811

..3.....97.......2019.........54773........1566319........47249907

..1....411......17031.......1566319......109797321......8964073263

..9...1897.....259811......47249907.....8964073263...1759241274383

..7...8741....2809217....1459651671...697824874477.350714115254871

.25..41689...38543397...45844870481.56238345975057

.25.201985..461143387.1455414376611

.83.987407.6074619247

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..83

EXAMPLE

Some solutions for n=4 k=4

.-1..0..0..0...-1..1..0..0...-1.-1..1..1....0.-1..1..1...-1..0..1.-1

.-1.-1.-1..0...-1..1.-1.-1...-1..1..0..0....0.-1..0..0...-1..0..1.-1

..1..1..1..1....0..0..1..0....1..1..0..0....0..0..1.-1....0..0.-1.-1

..0..0..0..0....0..0..1..0....1.-1.-1.-1....0..0..1.-1....1..1..1..1

CROSSREFS

Sequence in context: A134894 A143700 A036790 * A185559 A275842 A147640

Adjacent sequences:  A201844 A201845 A201846 * A201848 A201849 A201850

KEYWORD

nonn,tabl

AUTHOR

R. H. Hardin Dec 06 2011

STATUS

approved

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Last modified December 8 14:38 EST 2019. Contains 329865 sequences. (Running on oeis4.)