A202966 Number of arrays of 6 integers in -n..n with sum zero and adjacent elements differing in absolute value

0, 200, 1936, 9884, 33736, 90604, 207184, 421620, 785504, 1366876, 2251016, 3543320, 5371856, 7888384, 11270788, 15726488, 21492408, 28838244, 38069472, 49527504, 63592532, 80687412, 101276728, 125870512, 155027684, 189355324

Offset

1,2

Comments

Row 4 of A202962

Links

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

Formula

Empirical: a(n) = 2*a(n-1) -3*a(n-4) +a(n-5) +a(n-6) +a(n-9) +a(n-10) -3*a(n-11) +2*a(n-14) -a(n-15)

Example

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

Crossrefs

Sequence in context: A258921 A258918 A129641 * A218846 A219425 A341545

Adjacent sequences: A202963 A202964 A202965 * A202967 A202968 A202969

Keyword

nonn

Author

R. H. Hardin Dec 26 2011

Status

approved