OFFSET
1,6
COMMENTS
Column 4 of A193986
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..89
Christopher R. H. Hanusa, Thomas Zaslavsky, A q-queens problem. VII. Combinatorial types of nonattacking chess riders, arXiv:1906.08981 [math.CO], 2019.
FORMULA
Empirical: a(n) = 6*a(n-1) -12*a(n-2) +2*a(n-3) +27*a(n-4) -36*a(n-5) +36*a(n-7) -27*a(n-8) -2*a(n-9) +12*a(n-10) -6*a(n-11) +a(n-12)
Contribution from Vaclav Kotesovec, Aug 31 2012: (Start)
Empirical: G.f.: -x^6*(18 + 125*x + 267*x^2 + 279*x^3 + 151*x^4)/((-1+x)^9*(1+x)^3)
Empirical: a(n) = 87*n/40 - 57*n^2/32 - 253*n^3/96 + 1385*n^4/384 - 139*n^5/80 + 27*n^6/64 - 5*n^7/96 + n^8/384 + (3 - 11*n/8 + n^2/8)*floor(n/2)
(End)
EXAMPLE
Some solutions for 6X6X6
.......0............0............0............0............0............0
......0.0..........0.0..........1.0..........0.0..........0.1..........0.0
.....0.0.1........1.0.0........0.0.0........0.1.0........1.0.0........1.0.0
....0.1.0.0......0.0.0.1......0.0.0.1......0.0.0.1......0.0.0.0......0.0.1.0
...1.0.0.0.0....0.1.0.0.0....0.0.1.0.0....1.0.0.0.0....0.0.0.1.0....0.1.0.0.0
..0.0.0.0.1.0..0.0.0.0.1.0..0.1.0.0.0.0..0.0.1.0.0.0..0.0.1.0.0.0..0.0.0.0.0.1
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin Aug 10 2011
STATUS
approved