OFFSET
1,1
COMMENTS
Column 6 of A229428.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = (1/11404800)*n^12 + (1/211200)*n^11 + (37/345600)*n^10 + (143/103680)*n^9 + (27977/2419200)*n^8 + (83399/1209600)*n^7 + (321133/1036800)*n^6 + (35291/34560)*n^5 + (66941/28800)*n^4 + (614843/129600)*n^3 + (149511/30800)*n^2 + (19627/3465)*n + 4.
EXAMPLE
Some solutions for n=4
..2..2..1..0..0..0....1..0..0..0..0..0....2..2..1..1..1..0....2..2..2..1..1..1
..2..2..1..1..1..0....2..1..0..0..0..0....2..2..1..1..1..0....2..2..2..1..1..1
..2..2..1..1..1..0....2..1..0..0..0..0....2..2..2..1..1..0....2..2..2..1..1..1
..2..2..2..1..1..0....2..2..1..1..0..0....2..2..2..1..1..0....2..2..2..2..1..1
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Sep 22 2013
STATUS
approved