OFFSET
1,1
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = (589/3360)*n^8 + (349/210)*n^7 + (2483/360)*n^6 + (1317/80)*n^5 + (35819/1440)*n^4 + (1963/80)*n^3 + (19597/1260)*n^2 + (613/105)*n + 1.
Conjectures from Colin Barker, Oct 31 2018: (Start)
G.f.: x*(97 + 1022*x + 3086*x^2 + 2268*x^3 + 632*x^4 - 65*x^5 + 36*x^6 - 9*x^7 + x^8) / (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:
..1....0....1....3....3....1....2....4....0....4....2....4....3....2....1....2
..2....2....2....0....0....4....2....2....2....2....1....2....0....0....1....3
..0....0....0....3....2....2....0....0....1....0....0....0....0....0....1....1
..0....1....4....2....3....1....4....2....4....0....1....2....0....2....1....1
..2....0....1....1....0....0....1....0....0....4....2....1....3....2....1....3
..0....4....3....1....3....4....0....2....0....0....0....2....2....0....3....2
..4....0....0....1....2....2....3....0....2....2....4....0....2....3....3....0
..2....0....0....3....0....0....3....4....3....2....1....0....1....1....0....3
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, May 03 2014
STATUS
approved