OFFSET
1,1
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = (1/360)*n^6 + (1/40)*n^5 + (1/9)*n^4 + (7/24)*n^3 + (319/360)*n^2 + (101/60)*n + 1.
Conjectures from Colin Barker, Jan 09 2019: (Start)
G.f.: x*(4 - 15*x + 32*x^2 - 34*x^3 + 21*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=4:
..0..0..0..1....0..1..1..1....0..0..0..1....0..0..1..1....0..0..0..0
..0..0..1..0....0..1..1..1....0..0..0..1....0..0..1..1....0..0..1..1
..0..0..1..1....1..0..0..1....0..0..0..1....0..1..1..1....1..1..0..0
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Dec 29 2015
STATUS
approved