OFFSET
1,1
COMMENTS
Column 4 of A230708
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 185*a(n-2) -6851*a(n-4) +145707*a(n-6) -2849231*a(n-8) +30720183*a(n-10) -36007996*a(n-12) -743385180*a(n-14) +287330815*a(n-16) +8627923017*a(n-18) -12118273932*a(n-20) -29408445279*a(n-22) +45675171837*a(n-24) -13807146112*a(n-26) -2411662568755*a(n-28) +3802259458200*a(n-30) +3456476952882*a(n-32) +4249525502473*a(n-34) -5769431443156*a(n-36) -7037014662528*a(n-38) +2632063276930*a(n-40) +18416679443602*a(n-42) +9430615399362*a(n-44) +259673859628*a(n-46) +64576080600*a(n-48) +325261872*a(n-50)
EXAMPLE
Some solutions for n=2
..0..x..0..x..2..x..0....0..x..2..x..0..x..0....0..x..0..x..1..x..1
..x..1..x..0..x..1..x....x..1..x..0..x..1..x....x..1..x..1..x..2..x
..2..x..1..x..2..x..0....0..x..0..x..1..x..2....0..x..2..x..0..x..1
..x..0..x..2..x..1..x....x..0..x..2..x..0..x....x..2..x..0..x..2..x
..2..x..1..x..0..x..0....2..x..1..x..1..x..2....1..x..1..x..1..x..1
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Oct 28 2013
STATUS
approved