OFFSET
1,1
COMMENTS
Column 4 of A203728
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 9*a(n-1) -30*a(n-2) +30*a(n-3) +75*a(n-4) -243*a(n-5) +152*a(n-6) +360*a(n-7) -690*a(n-8) +130*a(n-9) +780*a(n-10) -780*a(n-11) -130*a(n-12) +690*a(n-13) -360*a(n-14) -152*a(n-15) +243*a(n-16) -75*a(n-17) -30*a(n-18) +30*a(n-19) -9*a(n-20) +a(n-21) for n>26
EXAMPLE
Some solutions for n=4
..1..2..2..2..2....1..1..1..2..1....1..2..2..2..2....0..1..1..1..0
..1..2..2..2..2....1..1..2..1..2....1..2..2..2..2....2..1..1..1..2
..1..2..2..2..2....0..2..1..2..1....1..2..2..2..2....1..2..2..2..2
..2..2..2..2..2....1..1..2..1..2....1..2..2..2..2....1..2..2..2..2
..2..2..2..2..2....0..2..1..2..1....1..2..2..2..2....2..2..2..2..2
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin Jan 05 2012
STATUS
approved