OFFSET
1,1
COMMENTS
Column 4 of A237249.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 80692*a(n-4) -2102571080*a(n-8) +17424111539232*a(n-12) -28895609836800*a(n-16) for n>20.
EXAMPLE
Some solutions for n=2
..0..1..2..1..2....2..1..0..1..0....2..2..2..2..2....1..2..2..1..1
..0..1..1..0..2....0..1..1..0..2....1..0..2..1..1....0..2..0..2..2
..2..2..0..2..0....0..0..0..0..0....0..1..0..1..2....1..1..2..0..1
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Feb 05 2014
STATUS
approved