OFFSET
1,1
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 14*a(n-1) - 85*a(n-2) + 294*a(n-3) - 639*a(n-4) + 906*a(n-5) - 839*a(n-6) + 490*a(n-7) - 164*a(n-8) + 24*a(n-9).
Empirical g.f.: x*(867 - 7109*x + 25244*x^2 - 52780*x^3 + 72501*x^4 - 66849*x^5 + 39534*x^6 - 13260*x^7 + 1944*x^8) / ((1 - x)^5*(1 - 2*x)^3*(1 - 3*x)). - Colin Barker, Nov 14 2018
EXAMPLE
Some solutions for n=4:
..2..2..2..1....2..2..0..0....2..1..1..0....0..0..0..0....1..0..1..0
..1..1..2..1....2..2..0..1....2..1..1..1....0..0..0..0....2..1..2..2
..1..1..2..1....2..2..0..1....0..0..0..0....0..0..0..0....2..1..2..2
..0..0..2..1....2..2..1..2....1..1..1..1....1..2..2..2....0..0..1..1
..0..0..2..1....1..1..1..2....0..0..2..2....0..1..1..1....0..0..1..1
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Nov 24 2014
STATUS
approved