OFFSET
1,1
COMMENTS
Column 2 of A219627.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = (1/12)*n^4 + (23/12)*n^2 + n.
Conjectures from Colin Barker, Jul 26 2018: (Start)
G.f.: x*(3 - 4*x + 2*x^2 + x^3) / (1 - x)^5.
a(n) = 5*a(n-1) - 10*a(n-2) + 10*a(n-3) - 5*a(n-4) + a(n-5) for n>5.
(End)
EXAMPLE
Some solutions for n=3:
..0..0....0..0....0..0....1..1....0..0....0..0....0..0....1..1....0..0....0..0
..0..1....0..0....0..1....0..0....1..1....0..0....0..0....1..1....0..1....0..0
..1..2....2..2....1..1....0..2....1..1....0..2....1..1....1..2....0..0....1..2
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Nov 24 2012
STATUS
approved