A223657 Number of 7Xn 0..1 arrays with all rows having a nonnegative second derivative, and all and columns having a positive second derivative in a quadratic least squares fit, with one and two element arrays taken as having a zero second derivative

60, 3600, 10425, 1059839, 24559913, 1119629805, 47882329200, 2061491256869, 95329202955957, 6980023496929171, 335311367775542739, 17119067750905601475, 1054799368422675063804, 74856492204365399292957

Offset

1,1

Comments

Row 5 of A223652

Links

Table of n, a(n) for n=1..14.

Example

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

Crossrefs

Sequence in context: A180373 A264947 A004297 * A264369 A053401 A375666

Adjacent sequences: A223654 A223655 A223656 * A223658 A223659 A223660

Keyword

nonn

Author

R. H. Hardin Mar 25 2013

Status

approved