OFFSET
1,1
COMMENTS
Column 7 of A220032.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..68
FORMULA
Empirical: a(n) = (1/720)*n^6 + (7/240)*n^5 + (11/144)*n^4 + (25/48)*n^3 + (263/90)*n^2 + (29/20)*n - 4 for n>2.
Conjectures from Colin Barker, Jul 30 2018: (Start)
G.f.: x*(7 - 31*x + 76*x^2 - 115*x^3 + 113*x^4 - 66*x^5 + 17*x^6 + x^7 - x^8) / (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>9.
(End)
EXAMPLE
Some solutions for n=3:
..1..1..0..0..0..0..0....1..1..1..0..0..0..0....1..0..0..0..0..0..0
..1..1..0..0..0..0..0....1..1..1..1..1..0..0....1..1..1..0..0..0..0
..1..1..0..0..0..0..0....1..1..1..1..1..0..0....1..1..1..1..0..0..0
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Dec 03 2012
STATUS
approved