A220013 - OEIS

%I #10 Feb 12 2026 14:12:51

%S 20,58,560,4474,29055,172143,983187,5489377,29766873,155831210,

%T 787372571,3852104643,18307862344,84697562976,381831482922,

%U 1679012288699,7209808373614,30272302102169,124439451139499,501340832583866

%N Number of 4 X n arrays of the minimum value of corresponding elements and their horizontal, vertical or antidiagonal neighbors in a random, but sorted with lexicographically nondecreasing rows and nonincreasing columns, 0..3 4 X n array.

%C Row 4 of A220010.

%H R. H. Hardin, <a href="/A220013/b220013.txt">Table of n, a(n) for n = 1..210</a>

%e Some solutions for n=3

%e ..1..0..0....1..0..0....0..0..0....1..0..0....2..1..1....0..0..0....2..0..0

%e ..0..0..0....1..0..0....0..0..0....1..0..0....1..1..1....0..0..0....2..0..0

%e ..0..0..1....2..2..3....2..0..0....2..0..0....1..1..1....1..1..1....2..2..0

%e ..2..2..3....2..3..3....0..0..0....3..0..0....3..3..3....1..1..2....2..0..0

%Y Cf. A220010.

%K nonn

%O 1,1

%A _R. H. Hardin_, Dec 03 2012