OFFSET
1,1
COMMENTS
Column 4 of A208118.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 2*a(n-1) + 2*a(n-2) - 6*a(n-3) + 6*a(n-5) - 2*a(n-6) - 2*a(n-7) + a(n-8).
Conjectures from Colin Barker, Jun 28 2018: (Start)
G.f.: x*(9 + 63*x + 45*x^2 + 67*x^3 + 11*x^4 - 3*x^5 - x^6 + x^7) / ((1 - x)^5*(1 + x)^3).
a(n) = n^4 + 4*n^3 + 6*n^2 + 4*n + 1 for n even.
a(n) = n^4 + 4*n^3 + 4*n^2 for n odd.
(End)
EXAMPLE
Some solutions for n=4:
..0..1..1..1....1..1..0..0....1..1..0..1....1..1..1..0....1..0..0..1
..1..0..0..1....0..0..1..1....1..0..1..1....0..1..1..1....0..1..1..0
..0..0..1..1....1..1..0..0....1..0..0..1....1..1..1..0....1..0..0..1
..1..0..0..1....0..0..1..1....0..0..1..1....0..1..1..0....0..1..1..0
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Feb 23 2012
STATUS
approved