OFFSET
1,1
COMMENTS
Row 4 of A223999.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = (1/2880)*n^8 + (1/180)*n^7 + (25/288)*n^6 + (169/180)*n^5 + (18649/2880)*n^4 + (4247/90)*n^3 + (2719/16)*n^2 - (6649/30)*n - 17 for n>4.
Conjectures from Colin Barker, Aug 25 2018: (Start)
G.f.: x*(81 + 64*x - 1241*x^2 + 2851*x^3 - 2540*x^4 + 248*x^5 + 1398*x^6 - 1380*x^7 + 796*x^8 - 347*x^9 + 88*x^10 - x^11 - 3*x^12) / (1 - x)^9.
a(n) = 9*a(n-1) - 36*a(n-2) + 84*a(n-3) - 126*a(n-4) + 126*a(n-5) - 84*a(n-6) + 36*a(n-7) - 9*a(n-8) + a(n-9) for n>13.
(End)
EXAMPLE
Some solutions for n=3:
..0..0..1....1..1..1....0..0..1....0..1..1....0..1..2....1..1..1....0..1..1
..0..2..2....1..1..1....0..1..1....1..1..1....0..1..1....1..1..2....1..1..1
..1..1..2....0..1..2....0..0..1....1..2..2....0..0..2....0..2..2....0..1..1
..1..2..2....0..0..1....0..0..0....0..2..2....0..0..1....2..2..2....0..0..1
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Mar 30 2013
STATUS
approved