OFFSET
1,1
COMMENTS
Row 3 of A219816.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = (1/362880)*n^9 - (1/40320)*n^8 + (13/60480)*n^7 + (1/2880)*n^6 + (305/3456)*n^5 - (1927/5760)*n^4 + (25129/45360)*n^3 + (58243/3360)*n^2 - (135179/2520)*n + 58 for n>3.
Conjectures from Colin Barker, Jul 28 2018: (Start)
G.f.: x*(6 - 44*x + 172*x^2 - 455*x^3 + 857*x^4 - 1142*x^5 + 1051*x^6 - 640*x^7 + 242*x^8 - 48*x^9 - x^10 + 4*x^11 - x^12) / (1 - x)^10.
a(n) = 10*a(n-1) - 45*a(n-2) + 120*a(n-3) - 210*a(n-4) + 252*a(n-5) - 210*a(n-6) + 120*a(n-7) - 45*a(n-8) + 10*a(n-9) - a(n-10) for n>13.
(End)
EXAMPLE
Some solutions for n=3:
..1..0..0....1..0..0....2..1..1....0..0..0....1..0..0....1..0..0....0..0..0
..2..0..0....1..1..0....2..1..1....0..0..0....1..1..0....1..0..0....1..0..0
..2..0..0....2..1..1....2..2..1....2..1..1....2..2..1....1..0..0....2..2..2
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Nov 28 2012
STATUS
approved