A223626 Number of 2Xn 0..1 arrays with row sums nondecreasing and column sums unimodal

3, 11, 35, 98, 260, 643, 1563, 3631, 8407, 18833, 42313, 92621, 203973, 439525, 954373, 2033480, 4369630, 9232317, 19680561, 41311764, 87507822, 182738699, 385095795, 800788788, 1680371358, 3482028637, 7280492521, 15041978366

Offset

1,1

Comments

Row 2 of A223625

Links

R. H. Hardin, Table of n, a(n) for n = 1..210

Example

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

Crossrefs

Sequence in context: A361435 A094308 A166046 * A088578 A320683 A027060

Adjacent sequences: A223623 A223624 A223625 * A223627 A223628 A223629

Keyword

nonn

Author

R. H. Hardin Mar 24 2013

Status

approved