A199938 Number of -3..3 arrays x(0..n-1) of n elements with zeroth through n-1st differences all nonzero.

6, 30, 142, 660, 3042, 13890, 63260, 287514, 1305394, 5924042, 26877500, 121920302, 553009230, 2508114154, 11375127276, 51589452156

Offset

1,1

Comments

Column 3 of A199943.

Links

Table of n, a(n) for n=1..16.

Example

Some solutions for n=6
.-2....2....3....3...-3...-3...-2...-1....2...-1...-3....3...-1....3...-2....3
..1....1...-2....1...-1...-2....1....3....3....3....2....2....1...-1...-3....1
.-3...-1....2....3....3....2...-2....2...-2...-1...-3...-1...-1....1...-1...-3
.-1....1...-1...-3...-3...-1...-3...-2....2...-2...-1...-3....2....2...-3...-1
..3....2....3....1....2....3....3....3...-2....1...-2....2...-2....1....1....3
.-3....1...-2...-1....1...-2...-2...-3...-3...-2....1....1....2...-1...-2...-1

Crossrefs

Cf. A199943.

Sequence in context: A002457 A137400 A220830 * A285195 A307321 A026749

Adjacent sequences: A199935 A199936 A199937 * A199939 A199940 A199941

Keyword

nonn

Author

R. H. Hardin, Nov 12 2011

Status

approved