OFFSET
1,2
COMMENTS
Every 0 is next to 0 2's, every 1 is next to 1 4's, every 2 is next to 2 3's, every 3 is next to 3 0's, every 4 is next to 4 1's.
Column 4 of A196786.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 2*a(n-1) +10*a(n-2) +15*a(n-3) -a(n-4) -6*a(n-5) -28*a(n-6) -14*a(n-7) +13*a(n-8) -13*a(n-9) +3*a(n-10).
Empirical g.f.: x*(1 + 5*x + 15*x^2 - 18*x^3 + 13*x^4 - 47*x^5 + x^6 - 17*x^7 + 12*x^8 + 3*x^9) / (1 - 2*x - 10*x^2 - 15*x^3 + x^4 + 6*x^5 + 28*x^6 + 14*x^7 - 13*x^8 + 13*x^9 - 3*x^10). - Colin Barker, May 09 2018
EXAMPLE
Some solutions for n=5:
..0..3..0..0....0..3..0..0....0..0..3..0....0..0..3..0....0..0..0..0
..3..0..0..3....0..0..0..0....0..0..0..0....0..3..0..3....0..3..0..0
..0..3..0..0....3..0..0..0....3..0..0..0....0..3..0..0....0..1..0..0
..0..3..0..0....0..0..0..0....0..0..0..0....0..0..0..0....1..4..1..0
..0..0..3..0....0..3..0..0....0..0..0..0....0..3..0..0....0..1..0..0
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Oct 06 2011
STATUS
approved