A210782 Number of nX2 1..4 arrays with no element with value z exactly a city block distance of z from another element with value z

15, 176, 1533, 8824, 40038, 167910, 710895, 3139374, 14621105, 73775740, 381369393, 1896558198, 8898865547, 40479815828, 186751218361, 891575695494, 4361545055817, 21344723416559, 102849312863141, 487830504402191

Offset

1,1

Comments

Column 2 of A210788

Links

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

Example

Some solutions for n=4
..4..2....3..3....3..4....2..4....1..3....2..1....4..4....4..2....3..1....3..3
..3..3....2..1....4..1....1..3....2..2....2..4....1..2....3..2....2..2....2..1
..1..3....1..4....2..4....3..4....4..3....3..4....3..1....4..4....3..1....4..4
..2..1....4..1....1..3....1..3....1..4....4..2....1..3....4..1....4..3....4..1

Crossrefs

Sequence in context: A184285 A120995 A024197 * A071535 A081043 A155000

Adjacent sequences: A210779 A210780 A210781 * A210783 A210784 A210785

Keyword

nonn

Author

R. H. Hardin Mar 26 2012

Status

approved