A188238 Number of nondecreasing arrangements of 5 numbers in -(n+3)..(n+3) with sum zero and not more than two numbers equal.

58, 119, 221, 374, 598, 903, 1317, 1852, 2540, 3397, 4459, 5744, 7296, 9133, 11303, 13830, 16766, 20135, 23997, 28378, 33342, 38919, 45177, 52148, 59908, 68489, 77971, 88392, 99836, 112341, 125999, 140850, 156990, 174463, 193369, 213754, 235726

Offset

1,1

Comments

Row 5 of A188236.

Links

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

Formula

Empirical: a(n) = 2*a(n-1) - a(n-3) - 2*a(n-5) + 2*a(n-6) + a(n-8) - 2*a(n-10) + a(n-11).

Empirical g.f.: x*(58 + 3*x - 17*x^2 - 10*x^3 - 31*x^4 + 44*x^5 + 7*x^6 + 20*x^7 - 13*x^8 - 37*x^9 + 22*x^10) / ((1 - x)^5*(1 + x)^2*(1 + x^2)*(1 + x + x^2)). - Colin Barker, Apr 27 2018

Example

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

Crossrefs

Cf. A188236.

Sequence in context: A354448 A181462 A260603 * A044245 A044626 A039536

Adjacent sequences: A188235 A188236 A188237 * A188239 A188240 A188241

Keyword

nonn

Author

R. H. Hardin, Mar 24 2011

Status

approved