A201847 T(n,k)=Number of zero-sum nXk -1..1 arrays with every element equal to at least one horizontal or vertical neighbor

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

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