A201876 Number of zero-sum -n..n arrays of 5 elements with first and second differences also in -n..n

5, 45, 169, 443, 977, 1905, 3373, 5555, 8655, 12901, 18541, 25891, 35207, 46827, 61141, 78483, 99295, 124019, 153047, 186915, 226123, 271207, 322711, 381229, 447347, 521711, 605043, 697945, 801117, 915391, 1041415, 1180073, 1332161

Offset

1,1

Comments

Row 5 of A201873

Links

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

Formula

Empirical: a(n) = a(n-1) -a(n-2) +2*a(n-3) -a(n-4) +2*a(n-5) -a(n-6) -a(n-8) -a(n-9) +a(n-10) -2*a(n-11) +3*a(n-12) -3*a(n-13) +3*a(n-14) -3*a(n-15) +2*a(n-16) -a(n-17) +a(n-18) +a(n-19) +a(n-21) -2*a(n-22) +a(n-23) -2*a(n-24) +a(n-25) -a(n-26) +a(n-27)

Example

Some solutions for n=10
.-9....7....5...-7...10....5....1....5...-5...-3....7....1....4...-3....1....7
.-7....1...-2...-3....5....3....0....6....2....2....6....0...-4...-2....0....0
..2...-5...-2....4...-3....4....1....0....5....4...-2...-4...-3...-2....0....0
..8...-3....0....6...-6...-2...-2...-6....0...-1...-4...-3...-3....3....1...-3
..6....0...-1....0...-6..-10....0...-5...-2...-2...-7....6....6....4...-2...-4

Crossrefs

Sequence in context: A003185 A302276 A302726 * A351426 A027801 A079139

Adjacent sequences: A201873 A201874 A201875 * A201877 A201878 A201879

Keyword

nonn

Author

R. H. Hardin Dec 06 2011

Status

approved