A219501 - OEIS

%I #5 Dec 26 2023 16:51:36

%S 7,13,45,126,281,550,995,1703,2793,4424,6804,10200,14949,21470,30277,

%T 41993,57365,77280,102782,135090,175617,225990,288071,363979,456113,

%U 567176,700200,858572,1046061,1266846,1525545,1827245,2177533,2582528

%N Number of n X 7 arrays of the minimum value of corresponding elements and their horizontal or vertical neighbors in a random, but sorted with lexicographically nondecreasing rows and nonincreasing columns, 0..1 n X 7 array.

%C Column 7 of A219502.

%F Empirical: a(n) = (1/720)*n^6 + (1/240)*n^5 + (23/144)*n^4 + (13/16)*n^3 + (331/180)*n^2 + (311/60)*n - 27 for n>3.

%e Some solutions for n=3

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

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

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

%Y Cf. A219502.

%K nonn

%O 1,1

%A _R. H. Hardin_, Nov 20 2012