A202251 Number of zero-sum -7..7 arrays of n elements with adjacent element differences also in -7..7

1, 7, 75, 779, 8211, 88301, 960501, 10536609, 116366779, 1292162535, 14412747241, 161362353297, 1812334370533, 20410840535049, 230416525827147, 2606567584536987, 29540755940559963, 335338507713978229

Offset

1,2

Comments

Column 7 of A202252

Links

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

Example

Some solutions for n=6
.-3....3....6...-2...-7...-5....6...-5...-5....1...-4....3....5...-2....4...-3
..3....3....0...-1...-7...-2...-1....2...-1....4....3....4...-2...-5....0...-2
..3...-3....1....3....0....5....3....3....2...-2....2...-2....2...-3...-6....1
.-4....4...-3....0....7...-1...-1...-1....2....4...-1...-6....0...-1....1...-2
..3...-2...-3...-2....2....0...-3....1....0...-1....0...-1....1....6....4....1
.-2...-5...-1....2....5....3...-4....0....2...-6....0....2...-6....5...-3....5

Crossrefs

Sequence in context: A174243 A157706 A197763 * A365841 A243692 A258293

Adjacent sequences: A202248 A202249 A202250 * A202252 A202253 A202254

Keyword

nonn

Author

R. H. Hardin Dec 14 2011

Status

approved