OFFSET
1,1
COMMENTS
Column 2 of A230949.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 31*a(n-2) +375*a(n-4) +233*a(n-6) -7946*a(n-8) -884*a(n-10) -16296*a(n-12) -203520*a(n-14) +53120*a(n-16).
EXAMPLE
Some solutions for n=2:
..0..x..0..x..2....0..x..0..x..2....0..x..0..x..2....0..x..2..x..2
..x..1..x..3..x....x..1..x..3..x....x..1..x..3..x....x..1..x..3..x
..0..x..2..x..0....2..x..2..x..2....0..x..2..x..2....0..x..0..x..2
..x..3..x..1..x....x..3..x..1..x....x..1..x..1..x....x..3..x..3..x
..2..x..0..x..0....2..x..0..x..0....0..x..0..x..0....2..x..2..x..2
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Nov 01 2013
STATUS
approved