OFFSET
1,1
COMMENTS
Every 0 is next to 0 4's, every 1 is next to 1 4's, every 2 is next to 2 0's, every 3 is next to 3 2's, every 4 is next to 4 1's
Column 3 of A197307
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..200
FORMULA
Empirical: a(n) = 2*a(n-1) +3*a(n-2) +3*a(n-3) +4*a(n-4) +2*a(n-5) +10*a(n-6) +6*a(n-7) -7*a(n-8) -23*a(n-9) -27*a(n-10) -23*a(n-11) +5*a(n-12) +29*a(n-13) +15*a(n-14) +2*a(n-15)
EXAMPLE
Some solutions for n=4
..2..0..0....0..0..0....0..0..0....0..0..0....2..0..0....0..0..2....2..0..2
..0..0..2....2..2..2....0..0..0....0..0..2....0..2..2....0..0..0....0..0..0
..0..0..2....0..0..0....2..3..2....0..0..2....2..2..0....2..2..0....0..0..0
..2..0..0....2..0..0....0..2..0....0..0..0....0..0..2....0..2..0....2..0..0
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin Oct 13 2011
STATUS
approved