OFFSET
1,3
COMMENTS
Column 3 of A252976.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = (1/90720)*n^9 + (1/2520)*n^8 + (19/3780)*n^7 + (7/360)*n^6 - (59/4320)*n^5 - (19/180)*n^4 + (5827/45360)*n^3 - (32/35)*n^2 + (3629/1260)*n - 2.
Empirical: G.f.: x^2*(1+8*x+18*x^2-70*x^3+94*x^4-78*x^5+43*x^6-14*x^7+2*x^8) / (x-1)^10. - R. J. Mathar, Nov 23 2015
EXAMPLE
Some solutions for n=4
..0..1..1....0..0..1....0..1..1....0..1..1....0..0..1....0..0..0....0..0..1
..0..1..2....0..0..1....1..1..2....0..1..2....0..1..2....0..1..1....0..0..1
..1..1..2....0..1..2....1..1..2....1..2..2....1..1..2....1..1..1....1..1..1
..2..2..2....1..2..2....1..1..2....1..2..2....1..2..2....1..1..2....2..2..2
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Dec 25 2014
STATUS
approved