OFFSET
1,2
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 36*a(n-1) - 463*a(n-2) + 2640*a(n-3) - 6700*a(n-4) + 6000*a(n-5).
Empirical g.f.: x*(1 - 28*x + 261*x^2 - 938*x^3 + 1120*x^4) / ((1 - 2*x)*(1 - 4*x)*(1 - 5*x)*(1 - 10*x)*(1 - 15*x)). - Colin Barker, Jan 11 2019
EXAMPLE
Some solutions for n=5:
..0..0..0..0....0..0..0..0....0..0..0..0....0..0..0..0....0..0..0..0
..0..0..1..0....0..1..1..0....0..0..0..1....0..0..0..1....0..1..0..1
..0..1..2..0....0..0..1..0....0..0..1..2....0..0..1..0....0..1..0..0
..0..0..1..0....0..0..0..1....0..0..0..1....0..1..0..1....0..0..1..1
..0..0..1..0....0..1..1..0....0..1..0..1....0..1..1..1....0..1..1..1
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jan 25 2016
STATUS
approved