OFFSET
1,1
COMMENTS
Column 2 of A231023
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
..x..0..x..2..x....x..0..x..2..x....x..0..x..2..x....x..0..x..0..x
..3..x..1..x..3....1..x..3..x..1....1..x..3..x..3....3..x..1..x..3
..x..2..x..0..x....x..2..x..2..x....x..2..x..0..x....x..0..x..2..x
..1..x..3..x..3....3..x..1..x..3....3..x..1..x..3....3..x..1..x..3
..x..0..x..2..x....x..0..x..0..x....x..0..x..0..x....x..0..x..0..x
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Nov 03 2013
STATUS
approved