A223581 Number of nX4 0..3 arrays with antidiagonals unimodal

256, 65536, 10240000, 1331200000, 173056000000, 22497280000000, 2924646400000000, 380204032000000000, 49426524160000000000, 6425448140800000000000, 835308258304000000000000

Offset

1,1

Comments

Column 4 of A223585

Links

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

Formula

Let U(z) = (z^6+15*z^5+115*z^4+405*z^3+964*z^2+660*z+720)/720

a(n) = U(min(n,4))^(max(n,4)-min(n,4)+1) * product{ U(i)^2 , i=1..(min(n,4)-1) }

a(n) = 130*a(n-1) for n>3

Example

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

Crossrefs

Sequence in context: A188909 A189110 A223803 * A133752 A144322 A223266

Adjacent sequences: A223578 A223579 A223580 * A223582 A223583 A223584

Keyword

nonn

Author

R. H. Hardin Mar 22 2013

Status

approved