OFFSET
1,1
COMMENTS
Column 4 of A247533
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = a(n-1) +4*a(n-2) -4*a(n-3) +18*a(n-4) -18*a(n-5) -78*a(n-6) +78*a(n-7) -67*a(n-8) +67*a(n-9) +386*a(n-10) -386*a(n-11) +22*a(n-12) -22*a(n-13) -686*a(n-14) +686*a(n-15) +125*a(n-16) -125*a(n-17) +616*a(n-18) -616*a(n-19) -178*a(n-20) +178*a(n-21) -340*a(n-22) +340*a(n-23) +130*a(n-24) -130*a(n-25) +80*a(n-26) -80*a(n-27) -40*a(n-28) +40*a(n-29) for n>30
EXAMPLE
Some solutions for n=6
..0....3....0....1....4....3....4....3....1....3....0....1....3....2....4....0
..1....4....4....2....1....2....2....4....0....2....3....0....0....4....1....0
..3....0....1....0....2....1....1....1....2....4....1....2....4....1....0....2
..4....1....3....1....3....2....3....0....3....1....2....1....1....3....3....2
..2....3....2....1....4....3....2....3....1....3....2....1....3....0....2....4
..1....4....2....2....1....4....2....2....2....0....3....2....2....2....1....0
..3....2....1....2....2....1....3....1....2....2....1....0....2....1....2....2
..2....3....1....1....3....0....1....2....3....1....0....3....3....1....3....2
..4....3....0....3....4....3....4....1....1....1....4....1....1....0....4....0
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Sep 18 2014
STATUS
approved