OFFSET
1,1
COMMENTS
Row 2 of A219381.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..165
FORMULA
Empirical: a(n) = (1/24)*n^4 - (1/4)*n^3 + (35/24)*n^2 + (15/4)*n - 9 for n>5.
Conjectures from Colin Barker, Jul 26 2018: (Start)
G.f.: x*(6 - 23*x + 39*x^2 - 35*x^3 + 15*x^4 + 5*x^5 - 14*x^6 + 13*x^7 - 6*x^8 + x^9) / (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>10.
(End)
EXAMPLE
Some solutions for n=3:
..0..0..2....1..0..1....0..0..1....0..0..1....0..0..2....0..0..0....1..1..1
..2..0..2....1..0..0....1..0..1....1..0..0....0..0..2....0..0..0....1..1..1
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Nov 19 2012
STATUS
approved