A227061 T(n,k) = Number of (n+k-1) X (n+k-1) binary arrays with k 1s in every row and column with rows and columns in lexicographically nondecreasing order.

1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 3, 5, 1, 1, 1, 5, 25, 13, 1, 1, 1, 8, 161, 272, 42, 1, 1, 1, 13, 1112, 7776, 4070, 155, 1, 1, 1, 21, 8787, 287311, 626649, 79221, 636, 1, 1, 1, 34, 76156, 13704640, 137393147, 70821384, 1906501, 2889, 1, 1, 1, 55, 728699, 809171699

Offset

1,9

Comments

Table starts

.1...1.....1......1......1....1.....1..1.1.1

.1...1.....1......1......1....1.....1..1.1

.1...2.....3......5......8...13....21.34

.1...5....25....161...1112.8787.76156

.1..13...272...7776.287311

.1..42..4070.626649

.1.155.79221

.1.636

Links

Table of n, a(n) for n=1..60.

Example

Some solutions for n=4 k=4
..0..0..0..1..1..1..1....0..0..0..1..1..1..1....0..0..0..1..1..1..1
..0..1..1..0..0..1..1....0..1..1..0..0..1..1....0..0..0..1..1..1..1
..0..1..1..0..1..0..1....0..1..1..0..1..0..1....0..1..1..0..0..1..1
..1..0..0..1..0..1..1....1..0..0..1..1..1..0....1..0..0..1..1..0..1
..1..0..1..1..1..0..0....1..0..1..0..0..1..1....1..1..1..0..0..1..0
..1..1..0..1..0..1..0....1..1..0..1..1..0..0....1..1..1..0..1..0..0
..1..1..1..0..1..0..0....1..1..1..1..0..0..0....1..1..1..1..0..0..0

Crossrefs

Column 2 is A229161(n+1).

Column 3 is A229162(n+2).

Column 4 is A229163(n+3).

Column 5 is A229164(n+4).

Row 3 is A000045(n+1).

Row 4 is A181344(n+3).

Sequence in context: A290759 A306245 A275043 * A201949 A291709 A326323

Adjacent sequences: A227058 A227059 A227060 * A227062 A227063 A227064

Keyword

nonn,tabl

Author

R. H. Hardin Sep 17 2013

Extensions

More terms from Sean A. Irvine, Sep 12 2019

Status

approved