A209391 Number of nX2 1..4 arrays with every element value z a city block distance of exactly z from another element value z

1, 2, 16, 152, 1449, 11655, 89469, 705803, 5771383, 45213223, 344221421, 2576621623, 19476715122, 147713174987, 1110131277687, 8315461638940, 62491630903612, 470960349189386, 3550021202822759, 26747955424745122

Offset

1,2

Comments

Column 2 of A209394

Links

R. H. Hardin, Table of n, a(n) for n = 1..122

Example

Some solutions for n=7
..1..4....3..4....3..3....2..3....3..2....4..3....2..3....4..2....1..4....4..1
..1..1....2..2....4..4....2..4....2..1....2..3....1..1....2..3....1..4....4..1
..4..2....2..2....1..3....2..2....2..1....3..2....2..2....3..1....1..4....3..1
..4..4....3..2....1..3....3..3....3..3....3..4....3..3....2..1....4..4....4..4
..1..2....2..4....4..4....4..2....2..1....3..1....2..2....4..3....1..1....4..3
..1..1....2..3....1..3....2..4....3..1....1..1....1..1....3..1....1..4....4..2
..4..4....3..2....1..3....3..3....2..3....1..3....3..2....1..1....4..4....2..4

Crossrefs

Sequence in context: A332566 A085510 A290785 * A259901 A209021 A209056

Adjacent sequences: A209388 A209389 A209390 * A209392 A209393 A209394

Keyword

nonn

Author

R. H. Hardin Mar 07 2012

Status

approved