A199937 Number of -2..2 arrays x(0..n-1) of n elements with zeroth through n-1st differences all nonzero

4, 12, 36, 104, 302, 868, 2490, 7132, 20424, 58418, 167036, 477412, 1364340, 3898236, 11138194, 31824012, 90926724, 259790792, 742259560, 2120727868, 6059178186, 17311798890, 49461883130, 141318491362, 403763748824

Offset

1,1

Comments

Column 2 of A199943

Links

Table of n, a(n) for n=1..25.

Example

Some solutions for n=6
.-2....2....2...-2....1...-2....1...-2...-1....1...-1...-1...-2...-1....2....2
..2...-1...-1....1....2....2...-2....1....1....2....1...-2....2...-2...-1....1
.-1....2...-2...-1....1....1...-1...-2....2...-1...-2....2....1....1....2....2
.-2...-1....1....2....2...-1....1....2....1....2...-1...-1....2....2...-2....1
..2....2....2...-2....1...-2...-2...-1....2...-1....2....1...-1...-2...-1....2
.-2....1...-1...-1...-1....1...-1....1...-1...-2....1...-2....1...-1....1...-1

Crossrefs

Sequence in context: A291732 A291264 A171849 * A290380 A003212 A156945

Adjacent sequences: A199934 A199935 A199936 * A199938 A199939 A199940

Keyword

nonn

Author

R. H. Hardin Nov 12 2011

Status

approved