OFFSET
1,1
COMMENTS
Row 5 of A200057.
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*(3 + 28*x + 76*x^2 + 135*x^3 + 168*x^4 + 159*x^5 + 105*x^6 + 51*x^7 + 10*x^8 + x^9) / ((1 - x)^5*(1 + x)^2*(1 + x^2)*(1 + x + x^2)). - Colin Barker, May 17 2018
EXAMPLE
Some solutions for n=6:
..1...-1....3...-6...-4...-1....1....4....6...-3....5...-1....1....1....1...-2
..0....2...-6....2....3...-5....2...-6...-1...-5...-6....2...-1....5...-2....6
..1...-2....4...-3...-3....5...-6....3....3....5....6...-4....4...-2....2...-5
.-3....5...-5....4....4...-1....4...-3...-5....1...-4....2...-3...-1...-5....1
..1...-4....4....3....0....2...-1....2...-3....2...-1....1...-1...-3....4....0
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Nov 13 2011
STATUS
approved