login
T(n,k)=Number of zero-sum nXk -1..1 arrays with every element equal to at least one horizontal or vertical neighbor
9

%I #5 Mar 31 2012 12:36:45

%S 0,1,1,1,5,1,3,25,25,3,1,97,125,97,1,9,411,2019,2019,411,9,7,1897,

%T 17031,54773,17031,1897,7,25,8741,259811,1566319,1566319,259811,8741,

%U 25,25,41689,2809217,47249907,109797321,47249907,2809217,41689,25,83,201985

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

%C Table starts

%C ..0......1..........1.............3..............1...............9

%C ..1......5.........25............97............411............1897

%C ..1.....25........125..........2019..........17031..........259811

%C ..3.....97.......2019.........54773........1566319........47249907

%C ..1....411......17031.......1566319......109797321......8964073263

%C ..9...1897.....259811......47249907.....8964073263...1759241274383

%C ..7...8741....2809217....1459651671...697824874477.350714115254871

%C .25..41689...38543397...45844870481.56238345975057

%C .25.201985..461143387.1455414376611

%C .83.987407.6074619247

%H R. H. Hardin, <a href="/A201847/b201847.txt">Table of n, a(n) for n = 1..83</a>

%e Some solutions for n=4 k=4

%e .-1..0..0..0...-1..1..0..0...-1.-1..1..1....0.-1..1..1...-1..0..1.-1

%e .-1.-1.-1..0...-1..1.-1.-1...-1..1..0..0....0.-1..0..0...-1..0..1.-1

%e ..1..1..1..1....0..0..1..0....1..1..0..0....0..0..1.-1....0..0.-1.-1

%e ..0..0..0..0....0..0..1..0....1.-1.-1.-1....0..0..1.-1....1..1..1..1

%K nonn,tabl

%O 1,5

%A _R. H. Hardin_ Dec 06 2011