OFFSET
1,1
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = (7/6)*n^6 + (28/3)*n^5 + (245/12)*n^4 + (47/2)*n^3 + (227/12)*n^2 + (26/3)*n + 1.
Conjectures from Colin Barker, Nov 11 2018: (Start)
G.f.: x*(83 + 401*x + 473*x^2 - 106*x^3 - 5*x^4 - 7*x^5 + x^6) / (1 - x)^7.
a(n) = 7*a(n-1) - 21*a(n-2) + 35*a(n-3) - 35*a(n-4) + 21*a(n-5) - 7*a(n-6) + a(n-7) for n>7.
(End)
EXAMPLE
Some solutions for n=6:
..4....4....1....2....4....0....4....4....2....1....4....3....1....4....4....0
..0....2....6....4....0....5....6....6....1....2....6....4....5....0....0....3
..0....1....2....6....2....2....4....5....3....5....1....1....5....0....3....5
..0....0....4....6....2....3....0....3....2....2....1....3....2....6....3....2
..3....3....2....1....2....2....5....1....5....5....1....1....4....0....5....2
..6....1....5....2....5....3....4....3....2....5....4....1....2....2....5....2
..3....3....0....2....3....0....4....6....4....0....2....4....2....4....3....1
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Nov 11 2014
STATUS
approved