A223671 Number of 4Xn 0..1 arrays with rows, diagonals and antidiagonals unimodal

16, 256, 1723, 6454, 18980, 49561, 119150, 267643, 567197, 1142224, 2198273, 4062420, 7238132, 12477929, 20877528, 33995513, 54002935, 83867606, 127578211, 190413722, 279263958, 403007495, 572953490, 803354343, 1111996481, 1520876908

Offset

1,1

Comments

Row 4 of A223669

Links

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

Formula

Empirical: a(n) = (1/112)*n^8 - (19/210)*n^7 + (59/45)*n^6 - (61/120)*n^5 - (8789/144)*n^4 + (99083/120)*n^3 - (10598579/2520)*n^2 + (1548737/140)*n - 11539 for n>6

Example

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

Crossrefs

Sequence in context: A189266 A208366 A207714 * A189619 A189691 A188742

Adjacent sequences: A223668 A223669 A223670 * A223672 A223673 A223674

Keyword

nonn

Author

R. H. Hardin Mar 25 2013

Status

approved