A223565 Number of nX4 0..1 arrays with antidiagonals unimodal

16, 256, 3136, 34496, 379456, 4174016, 45914176, 505055936, 5555615296, 61111768256, 672229450816, 7394523958976, 81339763548736, 894737399036096, 9842111389397056, 108263225283367616, 1190895478117043776

Offset

1,1

Comments

Column 4 of A223569

Links

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

Formula

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

a(n) = 11*a(n-1) for n>3

Example

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

Crossrefs

Sequence in context: A297377 A283860 A223660 * A223677 A207277 A294329

Adjacent sequences: A223562 A223563 A223564 * A223566 A223567 A223568

Keyword

nonn

Author

R. H. Hardin Mar 22 2013

Status

approved