A185409 - OEIS

%I #11 May 15 2017 16:06:29

%S 0,1,1,1,13,1,7,150,150,7,13,1848,5040,1848,13,55,22656,279918,279918,

%T 22656,55,133,278832,12205368,53808534,12205368,278832,133,463,

%U 3430776,595974240,9560464068,9560464068,595974240,3430776,463,1261,42221928

%N T(n,k)=1/7 the number of nXk 0..6 arrays with every element equal to exactly one or two of its horizontal and vertical neighbors

%C Table starts

%C ....0........1...........1.............7............13............55

%C ....1.......13.........150..........1848.........22656........278832

%C ....1......150........5040........279918......12205368.....595974240

%C ....7.....1848......279918......53808534....9560464068.1755419411964

%C ...13....22656....12205368....9560464068.6409594156632

%C ...55...278832...595974240.1755419411964

%C ..133..3430776.27536905674

%C ..463.42221928

%C .1261

%H R. H. Hardin, <a href="/A185409/b185409.txt">Table of n, a(n) for n = 1..49</a>

%e Some solutions for 4X3 with a(1,1)=0

%e ..0..3..6....0..0..0....0..0..4....0..0..3....0..3..6....0..3..3....0..0..0

%e ..0..3..6....4..4..4....0..4..4....3..3..3....0..3..6....0..2..2....4..4..4

%e ..2..4..4....1..5..4....0..5..5....3..2..2....5..0..6....1..1..1....5..5..6

%e ..2..2..2....1..5..5....4..4..4....1..1..1....5..0..6....6..6..6....0..0..6

%Y Column 1 is A015441(n-1)

%K nonn,tabl

%O 1,5

%A _R. H. Hardin_ Jan 26 2011