OFFSET
1,2
COMMENTS
Every 0 is next to 0 4's, every 1 is next to 1 3's, every 2 is next to 2 2's, every 3 is next to 3 0's, every 4 is next to 4 1's
Column 4 of A197090
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 6*a(n-1) +17*a(n-2) -26*a(n-3) -87*a(n-4) +142*a(n-5) -850*a(n-6) +95*a(n-7) +3242*a(n-8) -2530*a(n-9) +1754*a(n-10) -1012*a(n-11) +3424*a(n-12) -7495*a(n-13) +5596*a(n-14) +1534*a(n-15) -1254*a(n-16) -8051*a(n-17) +3682*a(n-18) -912*a(n-19) -646*a(n-20) +467*a(n-21) +623*a(n-22) -165*a(n-23) -426*a(n-24) +466*a(n-25) -101*a(n-26) +37*a(n-27) +15*a(n-28) -15*a(n-29) +5*a(n-30) for n>31
EXAMPLE
Some solutions for n=5
..0..1..0..0....0..0..2..2....0..0..2..2....0..3..0..0....0..3..0..0
..0..3..0..3....3..0..2..2....3..0..2..2....0..0..1..0....0..0..3..1
..0..0..1..0....0..3..0..0....0..0..3..0....0..0..3..0....1..3..0..0
..0..0..3..0....0..3..0..3....3..0..0..0....2..2..0..0....0..0..0..0
..0..0..0..0....0..0..3..0....0..0..3..0....2..2..0..0....0..3..0..0
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin Oct 10 2011
STATUS
approved