A223994 Number of nX3 0..2 arrays with antidiagonals unimodal and rows and diagonals nondecreasing

10, 76, 476, 2980, 18672, 117386, 739672, 4664776, 29428242, 185670484, 1171477424, 7391425016, 46636189140, 294251036912, 1856576835280, 11714070469768, 73909919072136, 466334575535548, 2942337620960936

Offset

1,1

Comments

Column 3 of A223999

Links

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

Formula

Empirical: a(n) = 10*a(n-1) -24*a(n-2) -2*a(n-3) +30*a(n-4) +96*a(n-5) -150*a(n-6) -108*a(n-7) +48*a(n-8) +270*a(n-9)

Example

Some solutions for n=3
..2..2..2....1..1..2....0..0..0....0..0..2....0..1..1....0..0..0....0..1..1
..2..2..2....1..1..2....0..0..2....1..2..2....1..2..2....0..0..1....0..0..2
..0..2..2....0..2..2....1..1..2....0..1..2....1..2..2....1..1..2....0..0..2

Crossrefs

Sequence in context: A368418 A108277 A061319 * A016149 A081199 A351132

Adjacent sequences: A223991 A223992 A223993 * A223995 A223996 A223997

Keyword

nonn

Author

R. H. Hardin Mar 30 2013

Status

approved