OFFSET
1,1
COMMENTS
Every 0 is next to 0 4's, every 1 is next to 1 0's, every 2 is next to 2 2's, every 3 is next to 3 1's, every 4 is next to 4 3's
Column 3 of A196718
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..200
FORMULA
Empirical: a(n) = 4*a(n-1) -3*a(n-2) +12*a(n-3) -22*a(n-4) -8*a(n-5) +39*a(n-6) -79*a(n-7) -147*a(n-8) +46*a(n-9) -13*a(n-10) +140*a(n-11) +701*a(n-12) -704*a(n-13) +732*a(n-14) -451*a(n-15) +1676*a(n-16) +1005*a(n-17) +1884*a(n-18) +296*a(n-19) +383*a(n-20) +244*a(n-21) +132*a(n-22) -160*a(n-23) -62*a(n-24) -10*a(n-25) +2*a(n-27)
EXAMPLE
Some solutions for n=4
..1..0..1....0..0..0....0..0..1....0..0..0....0..0..0....1..1..0....0..0..1
..2..2..1....0..0..0....2..2..2....1..1..1....1..1..1....0..1..1....0..2..2
..2..2..0....0..2..2....2..0..2....1..1..1....1..1..3....0..3..1....0..2..2
..1..0..0....0..2..2....2..2..2....0..0..0....0..0..1....1..1..0....0..0..1
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin Oct 05 2011
STATUS
approved