A221290 - OEIS

%I #6 Oct 31 2023 19:11:29

%S 1,1,1,2,4,1,4,16,12,1,7,52,92,37,1,12,200,673,556,114,1,21,792,5912,

%T 9107,3332,351,1,37,3080,48298,172904,123958,19996,1081,1,65,12164,

%U 396846,2890017,4983598,1686304,119972,3329,1,114,47827,3240527,49684593

%N T(n,k) = Equals two maps: number of n X k binary arrays indicating the locations of corresponding elements equal to exactly two of their horizontal and antidiagonal neighbors in a random 0..3 n X k array.

%C Table starts

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

%C .1.....4......16........52........200.........792.......3080.....12164

%C .1....12......92.......673.......5912.......48298.....396846...3240527

%C .1....37.....556......9107.....172904.....2890017...49684593.821323042

%C .1...114....3332....123958....4983598...172905144.6138441061

%C .1...351...19996...1686304..143511784.10344276279

%C .1..1081..119972..22931365.4129628435

%C .1..3329..719836.311813067

%C .1.10252.4319012

%C .1.31572

%C .1

%H R. H. Hardin, <a href="/A221290/b221290.txt">Table of n, a(n) for n = 1..70</a>

%e Some solutions for n=3, k=4

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

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

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

%Y Column 2 is A099098.

%Y Column 3 is A220932.

%Y Column 4 is A220933.

%Y Row 1 is A005251(n+1).

%Y Row 2 is A220936.

%K nonn,tabl

%O 1,4

%A _R. H. Hardin_, Jan 09 2013