login
Number of nX7 0..1 arrays with rows in nondecreasing lexicographic order and columns in nonincreasing lexicographic order, but with exactly two mistakes.
1

%I #4 Nov 28 2016 08:22:35

%S 56,5209,189595,5355983,141166787,3634987413,90752836672,

%T 2155380363189,48042054699217,999491681597761,19416161058987737,

%U 353517442918850559,6065787121333416262,98680235108923294584,1531317900358396738494

%N Number of nX7 0..1 arrays with rows in nondecreasing lexicographic order and columns in nonincreasing lexicographic order, but with exactly two mistakes.

%C Column 7 of A278778.

%H R. H. Hardin, <a href="/A278777/b278777.txt">Table of n, a(n) for n = 1..81</a>

%e Some solutions for n=3

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

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

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

%Y Cf. A278778.

%K nonn

%O 1,1

%A _R. H. Hardin_, Nov 28 2016