A219829 - OEIS

A219829

Number of 2Xn arrays of the minimum value of corresponding elements and their horizontal, diagonal or antidiagonal neighbors in a random, but sorted with lexicographically nondecreasing rows and columns, 0..3 2Xn array.

%I #8 Oct 03 2025 18:20:31

%S 10,13,38,87,176,370,721,1374,2533,4538,7924,13507,22510,36732,58771,

%T 92312,142492,216355,323411,476314,691675,991027,1401960,1959445,

%U 2707367,3700288,5005462,6705125,8899084,11707630,15274801,19772022,25402150

%N Number of 2Xn arrays of the minimum value of corresponding elements and their horizontal, diagonal or antidiagonal neighbors in a random, but sorted with lexicographically nondecreasing rows and columns, 0..3 2Xn array.

%C Row 2 of A219828

%H R. H. Hardin, <a href="/A219829/b219829.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = (1/40320)*n^8 - (1/3360)*n^7 - (1/2880)*n^6 + (31/240)*n^5 - (7913/5760)*n^4 + (2933/480)*n^3 + (12179/1120)*n^2 - (33527/280)*n + 202 for n>8

%e Some solutions for n=3

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

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

%K nonn

%O 1,1

%A _R. H. Hardin_, Nov 28 2012