A223843 Number of 7Xn 0..1 arrays with rows and antidiagonals unimodal and columns nondecreasing

8, 64, 342, 1356, 4325, 11749, 28369, 62869, 130891, 260219, 499470, 932402, 1701094, 3042926, 5348741, 9253153, 15773146, 26518532, 44008367, 72142211, 116895662, 187337832, 297106834, 466531024, 725652569, 1118500677, 1709080380

Offset

1,1

Comments

Row 7 of A223838

Links

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

Formula

Empirical: a(n) = (1/87178291200)*n^14 - (1/1779148800)*n^13 + (1/45619200)*n^12 - (53/136857600)*n^11 + (137/17418240)*n^10 - (1229/29030400)*n^9 + (739771/609638400)*n^8 - (1517923/87091200)*n^7 + (321517/691200)*n^6 - (12905723/3110400)*n^5 + (4378639787/119750400)*n^4 - (369357239/2494800)*n^3 + (61973609597/151351200)*n^2 - (519380551/360360)*n + 3759 for n>8

Example

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

Crossrefs

Sequence in context: A189190 A188875 A344854 * A356703 A267189 A181480

Adjacent sequences: A223840 A223841 A223842 * A223844 A223845 A223846

Keyword

nonn

Author

R. H. Hardin Mar 27 2013

Status

approved