A223627 Number of 3Xn 0..1 arrays with row sums nondecreasing and column sums unimodal

4, 26, 147, 751, 3560, 15778, 67030, 274631, 1088767, 4218662, 16015929, 59653826, 219063215, 794078382, 2843032061, 10081383128, 35429305737, 123436612116, 427070556002, 1467917436855, 5013326271265, 17031672794426, 57571509067410

Offset

1,1

Comments

Row 3 of A223625

Links

R. H. Hardin, Table of n, a(n) for n = 1..116

Example

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

Crossrefs

Sequence in context: A229278 A180226 A325587 * A144068 A204062 A121767

Adjacent sequences: A223624 A223625 A223626 * A223628 A223629 A223630

Keyword

nonn

Author

R. H. Hardin Mar 24 2013

Status

approved