OFFSET
1,1
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 5*a(n-4) for n>14.
Empirical g.f.: 4*x*(5200 + 2438*x + 876*x^2 + 1259*x^3 - 24318*x^4 - 9585*x^5 - 770*x^6 - 508*x^7 + 16*x^8 + 62*x^9 + 144*x^11 - 32*x^13) / (1 - 5*x^4). - Colin Barker, Oct 20 2018
EXAMPLE
Some solutions for n=5:
..0..0..0..2..1..0..0....2..0..1..2..0..0..0....1..2..0..0..0..1..2
..2..1..0..1..2..0..1....0..0..2..1..0..1..2....0..0..2..1..0..1..2
..1..2..0..0..0..2..1....1..2..0..0..0..2..1....1..0..1..2..0..0..0
..0..1..2..1..0..1..2....2..1..0..1..2..0..0....2..0..0..0..2..1..0
..0..0..0..2..0..0..0....0..0..0..2..0..1..0....1..2..1..0..1..2..0
..1..2..0..1..2..1..0....0..1..2..1..0..0..2....0..1..2..0..0..0..0
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jan 17 2014
STATUS
approved