OFFSET
1,1
COMMENTS
Column 4 of A204651.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 5*a(n-1) -9*a(n-2) +5*a(n-3) +5*a(n-4) -9*a(n-5) +5*a(n-6) -a(n-7) for n>9.
Conjectures from Colin Barker, Jun 08 2018: (Start)
G.f.: x*(48 - 150*x + 160*x^2 + 10*x^3 - 167*x^4 + 145*x^5 - 43*x^6 - 5*x^7 + 4*x^8) / ((1 - x)^6*(1 + x)).
a(n) = (1920 + 9776*n + 3480*n^2 + 540*n^3 + 90*n^4 + 4*n^5)/480 for n>2 and even.
a(n) = (1950 + 9776*n + 3480*n^2 + 540*n^3 + 90*n^4 + 4*n^5)/480 for n>2 and odd.
(End)
EXAMPLE
Some solutions for n=5:
..0..0..0..1..1....0..0..0..0..0....0..0..0..0..0....0..0..0..0..0
..0..0..0..1..1....0..0..0..0..0....0..0..0..0..0....0..0..0..0..0
..0..0..1..1..1....0..0..0..0..0....0..0..0..1..1....0..0..0..0..0
..1..1..1..1..1....0..0..0..0..1....0..0..0..1..1....0..0..0..0..1
..1..1..1..1..1....0..0..0..0..1....0..1..1..1..1....0..0..0..1..1
..1..1..1..1..1....0..0..0..1..0....0..1..1..1..1....0..0..1..1..1
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jan 17 2012
STATUS
approved