A200188 Number of -4..4 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, 8, 28, 120, 506, 2240, 9856, 44562, 199932, 914676, 4152696, 19143782, 87622590, 406118090, 1869888346, 8701509206, 40245967276, 187867050760, 872020225984, 4080661245080, 18995817588580, 89071683414448, 415623180115020

Offset

1,2

Comments

Column 4 of A200192

Links

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

Example

Some solutions for n=5
..1....2....1...-1....4....0...-2...-1....0...-4...-2....0....3....4....0....2
..4...-1...-4....4...-3....4....2...-3....3....3...-4...-3...-4...-4...-4...-2
.-3....2....2...-2....4...-2...-3....4...-2....1....3....2....4....0....3....2
..1...-3...-1....3...-4....1....4...-1....2....3....0...-1...-3...-3...-2...-2
.-3....0....2...-4...-1...-3...-1....1...-3...-3....3....2....0....3....3....0

Crossrefs

Sequence in context: A295914 A054857 A241893 * A255276 A110046 A027380

Adjacent sequences: A200185 A200186 A200187 * A200189 A200190 A200191

Keyword

nonn

Author

R. H. Hardin Nov 14 2011

Status

approved