OFFSET
1,2
COMMENTS
Column 9 of A215788
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 1385*a(n-2) -131648*a(n-4) -318070*a(n-6) -4160916*a(n-8) -1097892*a(n-10) +648*a(n-12)
EXAMPLE
Some solutions for n=4
..0..x..1..x..3..x..6..x..8....0..x..1..x..2..x..6..x.11
..x..2..x..5..x.10..x.13..x....x..3..x..5..x..8..x.12..x
..4..x..7..x.11..x.14..x.15....4..x..7..x.10..x.14..x.16
..x..9..x.12..x.16..x.17..x....x..9..x.13..x.15..x.17..x
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin Aug 23 2012
STATUS
approved