A202957 Number of arrays of n+2 integers in -3..3 with sum zero and adjacent elements differing in absolute value

20, 108, 414, 1936, 9872, 47732, 229714, 1134036, 5624396, 27808428, 138043018, 688575460, 3440536326, 17214566036, 86312920760, 433540643300, 2180469363652, 10980201879136, 55360485999044, 279418616308916, 1411643137279198

Offset

1,1

Comments

Column 3 of A202962

Links

R. H. Hardin, Table of n, a(n) for n = 1..210

Example

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

Crossrefs

Sequence in context: A278642 A135174 A173963 * A232586 A189437 A285698

Adjacent sequences: A202954 A202955 A202956 * A202958 A202959 A202960

Keyword

nonn

Author

R. H. Hardin Dec 26 2011

Status

approved