A283522 T(n,k)=Number of nXk 0..1 arrays with no 1 equal to more than three of its horizontal, vertical and antidiagonal neighbors, with the exception of exactly two elements.

0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 5, 20, 5, 0, 0, 28, 270, 270, 28, 0, 0, 145, 2763, 5988, 2763, 145, 0, 0, 703, 26662, 113984, 113984, 26662, 703, 0, 0, 3288, 241796, 2032993, 4069571, 2032993, 241796, 3288, 0, 0, 14980, 2115564, 34279720, 136572268

Offset

1,12

Comments

Table starts

.0.....0........0..........0.............0................0..................0

.0.....0........1..........5............28..............145................703

.0.....1.......20........270..........2763............26662.............241796

.0.....5......270.......5988........113984..........2032993...........34279720

.0....28.....2763.....113984.......4069571........136572268.........4331276717

.0...145....26662....2032993.....136572268.......8593156813.......510843580504

.0...703...241796...34279720....4331276717.....510843580504.....56913176714906

.0..3288..2115564..558718061..132684847054...29325852758117...6121670820777639

.0.14980.18020972.8877675769.3961612505725.1640229831666201.641300961433598943

Links

R. H. Hardin, Table of n, a(n) for n = 1..180

Formula

Empirical for column k:

k=1: a(n) = a(n-1)

k=2: [order 15]

k=3: [order 15] for n>19

k=4: [order 39] for n>43

Example

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

Crossrefs

Sequence in context: A302662 A261545 A093482 * A199363 A199588 A359977

Adjacent sequences: A283519 A283520 A283521 * A283523 A283524 A283525

Keyword

nonn,tabl

Author

R. H. Hardin, Mar 09 2017

Status

approved