A201438 Number of zero-sum -7..7 arrays of n elements with first through fourth differences also in -7..7

1, 7, 57, 297, 1333, 6019, 27087, 126147, 592487, 2795067, 13283639, 63243395, 302028473, 1447178413, 6955639001, 33526007827, 161977137395, 784134070729, 3802451672491, 18466210763809, 89797281724981, 437189848462945

Offset

1,2

Comments

Column 7 of A201439

Links

R. H. Hardin, Table of n, a(n) for n = 1..52

Example

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

Crossrefs

Sequence in context: A365102 A274721 A180817 * A202510 A042187 A201872

Adjacent sequences: A201435 A201436 A201437 * A201439 A201440 A201441

Keyword

nonn

Author

R. H. Hardin Dec 01 2011

Status

approved