A188419 Number of (4*n) X n binary arrays with rows in nonincreasing order, four 1's in every column and no more than three 1's in any row.

1, 5, 81, 3217, 252493, 33313408, 6720357785, 1943505834628, 768799728447441

Offset

1,2

Comments

Row 4 of A188416.

Links

Table of n, a(n) for n=1..9.

Example

All solutions for 8 X 2
..1..0....1..1....1..1....1..1....1..1
..1..0....1..1....1..1....1..0....1..1
..1..0....1..1....1..1....1..0....1..0
..1..0....1..1....1..0....1..0....1..0
..0..1....0..0....0..1....0..1....0..1
..0..1....0..0....0..0....0..1....0..1
..0..1....0..0....0..0....0..1....0..0
..0..1....0..0....0..0....0..0....0..0

Crossrefs

Cf. A188416.

Sequence in context: A009733 A009756 A336807 * A009634 A165435 A197443

Adjacent sequences: A188416 A188417 A188418 * A188420 A188421 A188422

Keyword

nonn

Author

R. H. Hardin, Mar 30 2011

Status

approved