OFFSET
1,1
COMMENTS
Every 0 is next to 0 3's, every 1 is next to 1 1's, every 2 is next to 2 2's, every 3 is next to 3 0's, every 4 is next to 4 4's
Column 3 of A196912
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..200
FORMULA
Empirical: a(n) = 2*a(n-1) +2*a(n-2) +16*a(n-3) +16*a(n-4) +5*a(n-5) -19*a(n-6) -53*a(n-7) -52*a(n-8) +15*a(n-9) +41*a(n-10) +24*a(n-11) -8*a(n-12) -28*a(n-13) -10*a(n-14) +7*a(n-15) +5*a(n-16) +4*a(n-17) -2*a(n-18)
EXAMPLE
Some solutions for n=4
..0..0..0....0..0..0....0..0..0....1..2..2....0..0..1....1..0..0....0..0..1
..2..2..0....2..2..1....0..0..0....1..2..2....0..0..1....1..0..1....0..0..1
..2..2..0....2..2..1....0..1..0....0..0..0....0..0..0....0..0..1....1..0..0
..0..0..0....0..0..0....0..1..0....0..0..0....0..1..1....1..1..0....1..0..0
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin Oct 07 2011
STATUS
approved