OFFSET
1,1
COMMENTS
Row 5 of A199847.
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) for n>12.
Empirical g.f.: x*(26 + 14*x + x^3 - 13*x^4 + 16*x^5 + 3*x^6 + 10*x^7 - 3*x^8 - 16*x^9 + 7*x^10 + x^11) / ((1 - x)^5*(1 + x)^2*(1 + x^2)*(1 + x + x^2)). - Colin Barker, May 16 2018
EXAMPLE
Some solutions for n=6:
..2....2....5....2....6....6....6....4....3....4....4....3....2....3....6....1
..3....3....6....1....2....4....6....3....1....1....3....2....0....4....2....2
..2....0...-3....1....3...-2...-1...-1....0...-2....0....2....1....4...-3....2
.-3...-2...-3....1...-6...-3...-5....0...-2...-1...-2...-3....0...-5...-2...-2
.-4...-3...-5...-5...-5...-5...-6...-6...-2...-2...-5...-4...-3...-6...-3...-3
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Nov 11 2011
STATUS
approved