A278777 Number of nX7 0..1 arrays with rows in nondecreasing lexicographic order and columns in nonincreasing lexicographic order, but with exactly two mistakes.

56, 5209, 189595, 5355983, 141166787, 3634987413, 90752836672, 2155380363189, 48042054699217, 999491681597761, 19416161058987737, 353517442918850559, 6065787121333416262, 98680235108923294584, 1531317900358396738494

Offset

1,1

Comments

Column 7 of A278778.

Links

R. H. Hardin, Table of n, a(n) for n = 1..81

Example

Some solutions for n=3
..1..0..1..1..0..0..0. .0..0..0..1..1..1..1. .1..1..0..0..1..0..0
..1..0..0..0..1..0..0. .0..1..0..1..0..0..0. .0..0..1..0..0..1..0
..1..0..0..0..1..0..0. .0..1..1..0..1..0..0. .1..1..0..1..0..0..1

Crossrefs

Cf. A278778.

Sequence in context: A271140 A278324 A009600 * A202565 A213693 A180372

Adjacent sequences: A278774 A278775 A278776 * A278778 A278779 A278780

Keyword

nonn

Author

R. H. Hardin, Nov 28 2016

Status

approved