A220794 - OEIS

%I #4 Dec 21 2012 06:17:35

%S 1,1,1,2,6,1,4,19,23,1,7,76,142,94,1,12,267,1753,1224,380,1,21,1074,

%T 15486,32507,9500,1494,1,37,4069,132977,602536,563715,74581,5939,1,65,

%U 15916,1115041,10731537,20635919,9507244,568257,23398,1,114,62161

%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, diagonal and antidiagonal neighbors in a random 0..2 nXk array

%C Table starts

%C .1.....1......2.......4........7.......12........21......37....65.114

%C .1.....6.....19......76......267.....1074......4069...15916.62161

%C .1....23....142....1753....15486...132977...1115041.9161834

%C .1....94...1224...32507...602536.10731537.183846017

%C .1...380...9500..563715.20635919

%C .1..1494..74581.9507244

%C .1..5939.568257

%C .1.23398

%C .1

%H R. H. Hardin, <a href="/A220794/b220794.txt">Table of n, a(n) for n = 1..49</a>

%e Some solutions for n=3 k=4

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

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

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

%Y Column 2 is A220372

%Y Row 1 is A005251(n+1)

%K nonn,tabl

%O 1,4

%A _R. H. Hardin_ Dec 21 2012