OFFSET
1,1
COMMENTS
Column 2 of A231651.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 6*a(n-1) - 12*a(n-2) + 19*a(n-3) - 32*a(n-4) + 15*a(n-5) - 13*a(n-6) + 13*a(n-7) + 10*a(n-8) + 7*a(n-9) + 5*a(n-10) + a(n-11) for n>12.
Empirical g.f.: x*(3 + 17*x - 70*x^2 + 80*x^3 - 178*x^4 + 97*x^5 - 49*x^6 + 100*x^7 + 73*x^8 + 48*x^9 + 31*x^10 + 6*x^11) / (1 - 6*x + 12*x^2 - 19*x^3 + 32*x^4 - 15*x^5 + 13*x^6 - 13*x^7 - 10*x^8 - 7*x^9- 5*x^10 - x^11). - Colin Barker, Mar 18 2018
EXAMPLE
Some solutions for n=3:
..1..1....2..2....0..0....1..1....1..2....0..0....0..0....0..0....2..0....0..1
..2..1....1..1....0..2....2..2....0..0....2..1....0..0....0..0....2..0....0..0
..1..1....1..1....0..0....1..1....0..0....0..0....2..1....1..2....0..0....1..0
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Nov 12 2013
STATUS
approved