A199851 Number of -n..n arrays x(0..6) of 7 elements with zero sum and no element more than one greater than the previous

153, 575, 1393, 2958, 5754, 10426, 17879, 29268, 46126, 70322, 104253, 150764, 213380, 296204, 404213, 543086, 719592, 941366, 1217343, 1557506, 1973400, 2477778, 3085247, 3811830, 4675676, 5696580, 6896795, 8300422, 9934376

Offset

1,1

Comments

Row 7 of A199847

Links

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

Formula

Empirical: a(n) = 2*a(n-1) -a(n-3) -a(n-5) +a(n-6) -2*a(n-7) +2*a(n-8) +a(n-9) -a(n-13) -2*a(n-14) +2*a(n-15) -a(n-16) +a(n-17) +a(n-19) -2*a(n-21) +a(n-22) for n>24

Example

Some solutions for n=6
..5....5....4....4....2....1....5....4....3....0....4....2....5....6....5....3
..4....6....3...-1....3....1....4....5....1....0....4....3....4....5....5....1
..0....2....3....0....1....2....4....3...-1....1...-2....4....4....3....4....1
..0....2...-1....0...-1....2....2...-3....0....2...-1....0....2....3...-5....1
.-2...-5....0....0....0...-2...-3...-2...-1....1....0....1...-5...-5...-4....0
.-3...-5...-5....0...-3...-1...-6...-1....0....0...-2...-5...-5...-6...-3...-3
.-4...-5...-4...-3...-2...-3...-6...-6...-2...-4...-3...-5...-5...-6...-2...-3

Crossrefs

Sequence in context: A371082 A325376 A256740 * A181775 A193249 A050209

Adjacent sequences: A199848 A199849 A199850 * A199852 A199853 A199854

Keyword

nonn

Author

R. H. Hardin Nov 11 2011

Status

approved