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A202047 T(n,k)=Number of zero-sum nXk -1..1 arrays with every element unequal to at most two horizontal and vertical neighbors 8

%I #5 Mar 31 2012 12:36:46

%S 1,3,3,7,19,7,19,73,73,19,51,335,415,335,51,141,1593,2921,2921,1593,

%T 141,393,7669,19541,31753,19541,7669,393,1107,37311,149149,359017,

%U 359017,149149,37311,1107,3139,184335,1067983,4188917,6221993,4188917,1067983

%N T(n,k)=Number of zero-sum nXk -1..1 arrays with every element unequal to at most two horizontal and vertical neighbors

%C Table starts

%C ....1.......3.........7.........19..........51..........141..........393

%C ....3......19........73........335........1593.........7669........37311

%C ....7......73.......415.......2921.......19541.......149149......1067983

%C ...19.....335......2921......31753......359017......4188917.....49553277

%C ...51....1593.....19541.....359017.....6221993....119412837...2229078023

%C ..141....7669....149149....4188917...119412837...3573771563.108356007319

%C ..393...37311...1067983...49553277..2229078023.108356007319

%C .1107..184335...8193025..594443301.43322352587

%C .3139..919889..60897081.7206865523

%C .8953.4620477.469758219

%H R. H. Hardin, <a href="/A202047/b202047.txt">Table of n, a(n) for n = 1..84</a>

%e Some solutions for n=5 k=3

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

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

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

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

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

%Y Column 1 is A002426

%K nonn,tabl

%O 1,2

%A _R. H. Hardin_ Dec 10 2011

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Last modified July 21 06:08 EDT 2024. Contains 374463 sequences. (Running on oeis4.)