OFFSET
1,3
COMMENTS
Column 3 of A231037.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 9*a(n-1) -a(n-2) +15*a(n-3) -374*a(n-4) +260*a(n-5) +256*a(n-6) +60*a(n-7) -176*a(n-8) -32*a(n-9).
Empirical g.f.: 2*x^3*(5 - 29*x + 184*x^3 - 148*x^4 - 32*x^5) / (1 - 9*x + x^2 - 15*x^3 + 374*x^4 - 260*x^5 - 256*x^6 - 60*x^7 + 176*x^8 + 32*x^9). - Colin Barker, Feb 09 2018
EXAMPLE
Some solutions for n=3:
..0..1..0....0..1..0....0..1..0....0..1..0....0..2..0....0..1..0....0..2..0
..1..2..2....2..2..0....2..2..1....0..2..2....0..1..1....2..2..2....1..1..2
..1..0..1....1..0..1....1..0..1....1..0..1....2..0..2....1..0..1....2..0..2
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Nov 03 2013
STATUS
approved