OFFSET
1,1
COMMENTS
Row 7 of A211849.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = (499/720)*n^6 + (2587/240)*n^5 + (10031/144)*n^4 + (11681/48)*n^3 + (179153/360)*n^2 + (8788/15)*n + 323.
Conjectures from Colin Barker, Jul 20 2018: (Start)
G.f.: x*(1731 - 5181*x + 9696*x^2 - 10295*x^3 + 6435*x^4 - 2210*x^5 + 323*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=3:
..0....0....0....0....0....0....0....0....0....0....0....0....0....0....0....0
..1....1....1....1....1....0....1....1....1....0....1....1....0....1....1....1
..1....1....1....1....0....1....1....1....1....1....1....1....1....0....1....1
..2....2....1....2....1....0....1....2....2....1....2....2....1....0....2....1
..2....2....2....2....1....0....2....2....2....2....2....2....2....2....2....2
..3....2....2....2....2....2....2....3....3....1....0....3....2....0....3....2
..3....3....2....3....1....2....2....3....2....1....0....3....3....2....2....2
..2....3....3....3....2....3....2....4....2....3....0....1....3....2....3....3
..3....4....3....4....2....3....3....4....2....3....3....1....4....3....3....2
..3....3....3....4....2....4....2....5....4....3....3....4....3....3....4....2
..4....4....4....2....2....4....2....5....4....3....3....4....4....4....4....4
..3....3....4....2....3....2....4....6....0....4....4....1....4....3....0....4
..3....3....4....2....3....2....4....6....0....3....4....1....5....3....0....0
..4....4....0....3....4....3....5....2....5....4....0....0....4....0....0....4
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Apr 22 2012
STATUS
approved