OFFSET
1,1
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = (1/6)*n^4 + (7/3)*n^3 + (23/6)*n^2 + (8/3)*n + 1.
Conjectures from Colin Barker, Dec 01 2018: (Start)
G.f.: x*(10 - 7*x + 5*x^2 - 5*x^3 + x^4) / (1 - x)^5.
a(n) = 5*a(n-1) - 10*a(n-2) + 10*a(n-3) - 5*a(n-4) + a(n-5) for n>5.
(End)
EXAMPLE
Some solutions for n=6:
..0....1....5....4....0....4....1....1....0....5....4....6....0....4....4....5
..6....4....0....6....3....2....6....1....2....3....2....6....1....6....1....4
..1....6....4....3....3....3....6....1....1....3....0....6....6....4....0....5
..0....4....5....4....0....4....4....1....1....5....0....0....0....3....4....5
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Dec 11 2014
STATUS
approved