OFFSET
1,1
COMMENTS
Column 7 of A207024
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = (55/24)*n^5 + (75/4)*n^4 + (275/8)*n^3 + (75/4)*n^2 - (295/6)*n.
Empirical G.f.: 25*x*(1+19*x-14*x^2+7*x^3-2*x^4)/(1-x)^6. [Colin Barker, May 22 2012]
EXAMPLE
Some solutions for n=4
..0..0..1..0..1..0..1....0..1..0..0..1..0..0....1..0..0..1..0..1..0
..0..1..0..1..0..0..1....1..0..1..0..1..0..0....0..1..0..0..1..0..0
..0..1..0..1..0..0..1....1..0..1..0..1..0..0....0..1..0..0..1..0..0
..0..1..0..1..0..0..1....1..0..1..0..1..0..0....0..1..0..0..1..0..0
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin Feb 14 2012
STATUS
approved