OFFSET
1,1
COMMENTS
Column 4 of A268327.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 30*a(n-1) -383*a(n-2) +2665*a(n-3) -10530*a(n-4) +20413*a(n-5) +1810*a(n-6) -87142*a(n-7) +111699*a(n-8) +116304*a(n-9) -292159*a(n-10) -83751*a(n-11) +371556*a(n-12) +93673*a(n-13) -257980*a(n-14) -122812*a(n-15) +60076*a(n-16) +59180*a(n-17) +15912*a(n-18) +1440*a(n-19)
EXAMPLE
Some solutions for n=10
..0....0....0....0....0....0....0....0....0....0....0....0....0....0....0....0
..1....1....1....0....1....1....1....1....0....1....0....0....1....0....1....1
..2....0....2....1....2....0....0....0....0....0....0....1....0....0....2....2
..0....2....0....0....1....2....0....0....1....2....1....2....1....1....0....0
..1....3....0....1....3....3....2....2....2....3....1....3....2....1....1....0
..0....2....3....2....2....2....3....1....1....4....1....1....0....2....0....0
..3....4....0....0....3....4....0....3....2....2....2....2....1....2....3....3
..4....0....3....2....2....0....0....1....3....0....1....1....2....3....1....1
..0....2....0....1....1....1....0....0....4....3....1....0....3....4....0....4
..1....1....0....1....4....4....4....0....0....1....2....1....4....3....4....0
..4....0....4....0....3....3....2....4....4....0....0....2....3....4....0....3
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Feb 01 2016
STATUS
approved