OFFSET
1,1
COMMENTS
Row 2 of A219578.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = (1/40)*n^5 - (5/24)*n^4 + (79/24)*n^3 - (91/24)*n^2 + (161/60)*n - 1 for n>1.
Conjectures from Colin Barker, Jul 26 2018: (Start)
G.f.: x*(4 - 11*x + 33*x^2 - 59*x^3 + 50*x^4 - 17*x^5 + 3*x^6) / (1 - x)^6.
a(n) = 6*a(n-1) - 15*a(n-2) + 20*a(n-3) - 15*a(n-4) + 6*a(n-5) - a(n-6) for n>7.
(End)
EXAMPLE
Some solutions for n=3:
..2..0..0....1..0..0....1..0..0....3..2..2....3..2..2....2..0..0....2..2..1
..2..1..0....2..1..0....1..1..0....3..3..2....3..2..2....3..1..0....2..1..1
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Nov 23 2012
STATUS
approved