A220242 - OEIS

%I #4 Dec 08 2012 13:33:09

%S 1,1,1,2,6,2,4,23,23,4,7,78,148,78,7,12,292,1131,1131,292,12,21,1066,

%T 8127,14976,8127,1066,21,37,3922,58091,219617,219617,58091,3922,37,65,

%U 14420,419164,3101079,5804389,3101079,419164,14420,65,114,53082,3016838

%N T(n,k)=Equals two maps: number of nXk binary arrays indicating the locations of corresponding elements equal to exactly two of their horizontal and vertical neighbors in a random 0..1 nXk array

%C Table starts

%C ...1.....1.......2........4.........7........12.......21........37.......65

%C ...1.....6......23.......78.......292......1066.....3922.....14420....53082

%C ...2....23.....148.....1131......8127.....58091...419164...3016838.21697096

%C ...4....78....1131....14976....219617...3101079.43677639.613533257

%C ...7...292....8127...219617...5804389.165087351

%C ..12..1066...58091..3101079.165087351

%C ..21..3922..419164.43677639

%C ..37.14420.3016838

%C ..65.53082

%C .114

%H R. H. Hardin, <a href="/A220242/b220242.txt">Table of n, a(n) for n = 1..59</a>

%e Some solutions for n=3 k=4

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

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

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

%Y Column 1 is A005251(n+1)

%K nonn,tabl

%O 1,4

%A _R. H. Hardin_ Dec 08 2012