login
A183914
Number of nondecreasing arrangements of n numbers in -6..6 with sum zero
2
1, 7, 25, 86, 252, 676, 1656, 3788, 8150, 16660, 32540, 61108, 110780, 194668, 332578, 553981, 901723, 1437269, 2247151, 3451798, 5216252, 7764392, 11396054, 16509188, 23626234, 33427622, 46791278, 64841876, 89008530, 121095602, 163364972
OFFSET
1,2
COMMENTS
Column 6 of A183917
LINKS
FORMULA
Empirical: a(n)=a(n-1)+2*a(n-2)-a(n-3)-a(n-4)-a(n-6)-2*a(n-7)+a(n-8)+2*a(n-9)+a(n-11)+2*a(n-12)-a(n-13)-a(n-14)+2*a(n-15)-a(n-16)-4*a(n-17)-3*a(n-20)+a(n-21)+3*a(n-22)+a(n-24)+4*a(n-25)-a(n-26)-a(n-27)+3*a(n-28)-a(n-29)-4*a(n-30)-4*a(n-33)-a(n-34)+3*a(n-35)-a(n-36)-a(n-37)+4*a(n-38)+a(n-39)+3*a(n-41)+a(n-42)-3*a(n-43)-4*a(n-46)-a(n-47)+2*a(n-48)-a(n-49)-a(n-50)+2*a(n-51)+a(n-52)+2*a(n-54)+a(n-55)-2*a(n-56)-a(n-57)-a(n-59)-a(n-60)+2*a(n-61)+a(n-62)-a(n-63)
EXAMPLE
Some solutions for n=4
.-5...-6...-2...-5...-3...-4...-6...-3...-4...-5...-6...-4...-4...-3...-6...-3
..0...-1...-1....0...-3....1...-1....1...-3...-2...-3...-1...-3...-1....0...-2
..1....1....0....0....1....1....2....1....3....2....4....2....1....1....0...-1
..4....6....3....5....5....2....5....1....4....5....5....3....6....3....6....6
CROSSREFS
Sequence in context: A220387 A155294 A155233 * A279216 A245769 A146933
KEYWORD
nonn
AUTHOR
R. H. Hardin Jan 07 2011
STATUS
approved