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 4's, every 4 is next to 4 0's
Column 3 of A197167
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..200
FORMULA
Empirical: a(n) = 2*a(n-1) +5*a(n-2) +21*a(n-3) +48*a(n-4) +168*a(n-5) +194*a(n-6) +40*a(n-7) -492*a(n-8) -713*a(n-9) -516*a(n-10) +152*a(n-11) +700*a(n-12) +538*a(n-13) +265*a(n-14) -160*a(n-15) -176*a(n-16) -53*a(n-17) -4*a(n-18) +26*a(n-19) +3*a(n-20) -10*a(n-21) -3*a(n-22)
EXAMPLE
Some solutions for n=4
..1..0..0....0..0..0....1..2..1....1..2..1....0..0..1....0..0..0....0..0..0
..2..0..0....1..1..0....0..2..1....0..0..0....1..0..2....0..0..0....0..2..1
..1..0..0....2..2..1....1..1..0....0..1..2....2..1..1....1..0..0....0..1..0
..0..0..0....1..0..0....2..1..0....0..0..1....0..0..0....2..1..0....0..0..0
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin Oct 10 2011
STATUS
approved