OFFSET
1,1
COMMENTS
Column 6 of A224625.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..38
FORMULA
Empirical: a(n) = 4*a(n-1) - 6*a(n-2) + 4*a(n-3) - a(n-4) + a(n-5) - 3*a(n-6) + 3*a(n-7) - a(n-8) for n>12.
Empirical g.f.: x*(43489 - 149704*x + 192875*x^2 - 112617*x^3 + 26798*x^4 - 43723*x^5 + 113448*x^6 - 96972*x^7 + 26141*x^8 + 195*x^9 + 65*x^10 + 4*x^11) / ((1 - x)^3*(1 - x + x^2)*(1 - x^2 - x^3)). - Colin Barker, Sep 02 2018
EXAMPLE
Some solutions for n=2:
..1..0..0..0..0..0..0..0..0..0....1..0..0..0..0..0..0..0..0..1
..1..0..0..0..0..0..0..0..0..1....1..0..0..0..0..0..0..0..0..2
..0..0..0..0..0..0..0..0..0..2....0..0..0..0..0..0..0..0..0..1
..2..0..0..0..0..0..0..0..0..1....2..0..0..0..0..0..0..0..0..0
..0..0..0..0..0..0..0..0..0..1....1..0..0..0..0..0..0..0..0..1
..0..0..0..0..0..0..0..0..0..1....1..0..0..0..0..0..0..0..0..1
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Apr 12 2013
STATUS
approved