OFFSET
1,1
COMMENTS
Row 3 of A249960.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = n^8 + (152/105)*n^7 + (62/15)*n^6 + (26/5)*n^5 + (1/2)*n^4 + (19/15)*n^3 + (28/15)*n^2 - (29/70)*n.
Conjectures from Colin Barker, Aug 21 2017: (Start)
G.f.: x*(15 + 762*x + 6561*x^2 + 15932*x^3 + 13281*x^4 + 3594*x^5 + 175*x^6) / (1 - x)^9.
a(n) = 9*a(n-1) - 36*a(n-2) + 84*a(n-3) - 126*a(n-4) + 126*a(n-5) - 84*a(n-6) + 36*a(n-7) - 9*a(n-8) + a(n-9) for n>9.
(End)
EXAMPLE
Some solutions for n=4:
..4....1....4....0....1....4....3....3....1....3....3....0....2....2....0....1
..4....1....3....2....3....1....2....4....4....1....2....2....2....0....2....1
..0....0....0....3....0....0....3....0....0....2....0....4....3....0....2....0
..0....1....0....3....2....4....3....0....0....0....3....0....3....4....0....3
..4....2....4....1....1....0....0....2....3....1....1....1....3....4....4....0
..2....0....1....3....0....1....4....3....1....0....0....3....3....4....4....3
..4....2....3....1....1....2....0....4....1....3....4....4....0....4....1....4
..1....1....4....2....2....3....3....3....1....1....2....4....2....3....0....4
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Nov 09 2014
STATUS
approved