A223654 Number of 4Xn 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

5, 25, 43, 229, 799, 3237, 16975, 58813, 262975, 1273157, 6142655, 26877117, 132748947, 716258257, 3072240791, 15826485913, 73962438259, 366204124645, 1830090585655, 8942164068501, 44436414147403, 225094702418657

Offset

1,1

Comments

Row 2 of A223652

Links

Table of n, a(n) for n=1..22.

Example

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

Crossrefs

Sequence in context: A294256 A056872 A029490 * A362092 A098947 A364584

Adjacent sequences: A223651 A223652 A223653 * A223655 A223656 A223657

Keyword

nonn

Author

R. H. Hardin Mar 25 2013

Status

approved