|
| |
|
|
A188183
|
|
Number of strictly increasing arrangements of 5 numbers in -(n+3)..(n+3) with sum zero
|
|
4
|
|
|
|
12, 32, 73, 141, 252, 414, 649, 967, 1394, 1944, 2649, 3523, 4604, 5910, 7483, 9343, 11538, 14090, 17053, 20451, 24342, 28754, 33751, 39361, 45654, 52662, 60459, 69079, 78602, 89064, 100551, 113101, 126804, 141702, 157891, 175413, 194370, 214808
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
|
OFFSET
|
1,1
|
|
|
COMMENTS
|
|
|
|
LINKS
|
|
|
|
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: a(n) = 427*n^2/144 +155*n/32 +5501/1728+23*n^4/288 +115*n^3/144 -3*(-1)^n*n/32-15*(-1)^n/64 +A057077(n+1)/8 -2*A061347(n+1)/27; g.f. -x*(12 +8*x +9*x^2 +7*x^3 +2*x^4 +7*x^5 +2*x^6 +3*x^7 -2*x^8 -5*x^9 +3*x^10) / ( (x^2+1) *(1+x+x^2) *(1+x)^2 *(x-1)^5 ). - R. J. Mathar, Mar 26 2011
|
|
|
EXAMPLE
|
Some solutions for n=5
.-5...-8...-7...-8...-6...-4...-8...-6...-8...-5...-8...-7...-6...-6...-8...-7
.-3...-3...-4...-6...-2...-3...-7...-5...-2...-3...-2...-4...-5...-5...-1...-6
.-1...-2....0....0...-1...-1....4...-2....2...-1....1...-2....2...-3....1....1
..3....5....4....6....2....0....5....6....3....1....3....6....3....6....3....4
..6....8....7....8....7....8....6....7....5....8....6....7....6....8....5....8
|
|
|
CROSSREFS
|
|
|
|
KEYWORD
|
nonn
|
|
|
AUTHOR
|
|
|
|
STATUS
|
approved
|
| |
|
|
