OFFSET
1,1
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..36
FORMULA
Empirical: a(n) = 41*a(n-4) -400*a(n-8) for n>13.
Empirical g.f.: x*(81 + 722*x + 1494*x^2 + 2356*x^3 + 2037*x^4 - 19182*x^5 - 39966*x^6 - 46736*x^7 - 72966*x^8 + 89680*x^9 + 174048*x^10 + 2800*x^11 - 17568*x^12) / ((1 - 2*x)*(1 + 2*x)*(1 + 4*x^2)*(1 - 5*x^2)*(1 + 5*x^2)). - Colin Barker, Oct 20 2018
EXAMPLE
Some solutions for n=5:
..0..2..0..0..0..2....2..1..0..1..1..2....0..0..0..0..1..2....0..2..1..0..1..1
..2..1..0..1..2..0....1..2..0..0..0..2....0..2..1..0..1..2....0..1..2..0..0..0
..0..0..0..2..1..0....0..1..2..1..0..1....0..1..2..0..0..0....0..0..0..2..1..0
..0..1..2..0..0..0....0..0..0..2..0..0....0..0..0..2..1..0....2..1..0..1..2..0
..1..2..1..0..1..2....1..2..0..1..2..1....2..1..0..1..2..0....0..2..0..0..0..2
..2..1..0..0..1..2....2..1..0..0..0..2....2..1..0..0..1..2....1..0..2..1..0..1
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jan 17 2014
STATUS
approved