A209390 Number of nX1 1..4 arrays with every element value z a city block distance of exactly z from another element value z

0, 1, 1, 3, 3, 13, 16, 42, 74, 161, 303, 631, 1212, 2446, 4847, 9714, 19142, 38031, 75367, 149813, 296961, 589537, 1169118, 2319453, 4603741, 9137804, 18132445, 35982420, 71413411, 141734249, 281295511, 558288679, 1107995542, 2198965721, 4364220336

Offset

1,4

Comments

Column 1 of A209394

Links

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

Example

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

Crossrefs

Sequence in context: A146020 A145948 A049768 * A363630 A095336 A072552

Adjacent sequences: A209387 A209388 A209389 * A209391 A209392 A209393

Keyword

nonn

Author

R. H. Hardin Mar 07 2012

Status

approved