A200187 Number of -3..3 arrays x(0..n-1) of n elements with zero sum, adjacent elements differing by more than one, and elements alternately increasing and decreasing.

1, 6, 14, 48, 144, 482, 1534, 5148, 16826, 56918, 188706, 642300, 2149072, 7348408, 24749244, 84919630, 287439908, 988917344, 3360535304, 11586463472, 39498606276, 136421151864, 466287543690, 1612808711870, 5524756100592

Offset

1,2

Comments

Column 3 of A200192

Links

R. H. Hardin, Table of n, a(n) for n = 1..200

Example

Some solutions for n=5
..3...-2...-1...-2...-1...-2....2...-2....0....2....2...-1...-3....3....0....2
.-3....3....3....2...-3....2...-2....2...-2...-3...-3....2....2...-3....2...-2
..0...-3...-3....0....2...-2....2....0....2....3....1...-1...-3....2...-3....1
.-3....2....3....2...-1....2...-3....3...-2...-2...-2....1....3...-3....3...-3
..3....0...-2...-2....3....0....1...-3....2....0....2...-1....1....1...-2....2

Crossrefs

Sequence in context: A294655 A005515 A114705 * A107301 A118432 A032404

Adjacent sequences: A200184 A200185 A200186 * A200188 A200189 A200190

Keyword

nonn

Author

R. H. Hardin, Nov 14 2011

Status

approved