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A188335 Number of nondecreasing arrangements of 5 nonzero numbers in -(n+3)..(n+3) with sum zero 1
40, 86, 166, 288, 472, 726, 1076, 1534, 2130, 2878, 3814, 4954, 6340, 7990, 9950, 12242, 14918, 18000, 21546, 25582, 30170, 35338, 41154, 47648, 54894, 62924, 71816, 81606, 92378, 104168, 117066, 131112, 146400, 162972, 180928, 200312, 221230 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Row 5 of A188333

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. -2*x*(20 +3*x -3*x^2 -2*x^3 -9*x^4 +14*x^5 +2*x^6 +7*x^7 -4*x^8 -12*x^9 +7*x^10) / ( (x^2+1) *(1+x+x^2) *(1+x)^2 *(x-1)^5 ). a(n) = 23*n^4/288 +175*n^3/144 +985*n^2/144 +1601*n/96 +25265/1728 -(-1)^n*(3*n/32+27/64) -2*A061347(n+1)/27 -A057077(n+1)/8. - R. J. Mathar, Mar 28 2011

EXAMPLE

Some solutions for n=6

.-4...-7...-4...-7...-5...-9...-6...-7...-5...-7...-9...-5...-9...-5...-8...-6

.-3...-3...-3...-4...-5...-7...-6...-4...-4...-4...-5...-4...-3...-3...-3...-6

..1...-1...-3....2....1....1....2....2...-1....3....3....2....2....1...-2...-1

..3....4....4....3....2....6....2....4....4....4....3....3....5....1....5....4

..3....7....6....6....7....9....8....5....6....4....8....4....5....6....8....9

CROSSREFS

Sequence in context: A160282 A243803 A203855 * A185718 A043414 A044178

Adjacent sequences:  A188332 A188333 A188334 * A188336 A188337 A188338

KEYWORD

nonn

AUTHOR

R. H. Hardin Mar 28 2011

STATUS

approved

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Last modified May 22 13:18 EDT 2017. Contains 286872 sequences.