OFFSET
1,1
COMMENTS
Every 0 is next to 0 3's, every 1 is next to 1 2's, every 2 is next to 2 1's, every 3 is next to 3 0's, every 4 is next to 4 4's
Column 3 of A196982
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..200
FORMULA
Empirical: a(n) = 2*a(n-1) +4*a(n-2) +22*a(n-3) +45*a(n-4) +166*a(n-5) +204*a(n-6) +94*a(n-7) -372*a(n-8) -674*a(n-9) -692*a(n-10) -170*a(n-11) +495*a(n-12) +655*a(n-13) +521*a(n-14) +107*a(n-15) -138*a(n-16) -139*a(n-17) -84*a(n-18) -15*a(n-19) +9*a(n-20) +3*a(n-21)
EXAMPLE
Some solutions for n=4
..1..1..2....0..0..0....1..2..1....2..1..0....2..1..0....0..0..0....1..1..0
..2..1..1....0..0..1....0..2..1....1..0..1....1..1..2....1..2..1....2..2..1
..2..1..1....1..1..2....1..1..0....1..1..2....0..0..1....0..0..0....1..0..0
..1..1..2....2..1..0....2..1..0....2..1..0....0..0..0....0..0..0....1..2..1
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin Oct 08 2011
STATUS
approved