OFFSET
1,1
COMMENTS
Column 3 of A240347
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 18*a(n-1) -105*a(n-2) +200*a(n-3) +242*a(n-4) -2119*a(n-5) +7083*a(n-6) -9004*a(n-7) -24192*a(n-8) +72426*a(n-9) -3118*a(n-10) -103236*a(n-11) -4239*a(n-12) +64281*a(n-13) +119026*a(n-14) -161710*a(n-15) +142844*a(n-16) -25892*a(n-17) -337024*a(n-18) +223288*a(n-19) +175280*a(n-20) -145120*a(n-21) -22528*a(n-22) +23040*a(n-23)
EXAMPLE
Some solutions for n=4
..2..2..0....2..0..0....0..2..2....0..0..0....0..0..2....0..0..0....0..2..0
..2..2..0....0..0..0....0..2..0....0..2..0....2..2..0....0..2..0....0..2..0
..0..2..2....2..0..2....0..0..2....0..0..2....0..0..0....0..2..2....0..0..3
..0..0..2....2..2..0....2..0..0....0..2..1....2..0..0....2..0..0....0..0..2
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Apr 04 2014
STATUS
approved