login
A200052
Number of -3..3 arrays x(0..n-1) of n elements with zero sum and elements alternately strictly increasing and strictly decreasing
1
1, 6, 22, 78, 288, 1098, 4224, 16432, 64310, 253692, 1003374, 3992358, 15908668, 63684848, 255153798, 1026057576, 4127971346, 16658240722, 67237254862, 272092306164, 1101134446908, 4466186295698, 18113540529096, 73607652658268
OFFSET
1,2
COMMENTS
Column 3 of A200057
LINKS
EXAMPLE
Some solutions for n=6
.-1...-2....0...-2...-1....1....0...-2...-1....3...-1....1....0....0...-2....1
.-3....0....2....1....1...-2....3....3...-3....0...-3...-2...-1....3....2...-1
..3...-1...-3...-2...-2....3...-1....1....2....2....3....3....3...-1....0....1
.-1....1....2....2....2...-3....3....3...-1...-3....0...-2....0....1....2...-1
..2...-1...-3....0...-2....1...-3...-3....2....1....3....2....1...-3...-2....1
..0....3....2....1....2....0...-2...-2....1...-3...-2...-2...-3....0....0...-1
CROSSREFS
Sequence in context: A217530 A111566 A372239 * A051945 A253070 A255461
KEYWORD
nonn
AUTHOR
R. H. Hardin Nov 13 2011
STATUS
approved