OFFSET
1,5
COMMENTS
Column 6 of A194492
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..42
FORMULA
Empirical: a(n) = (1/46080)*n^12 + (1/7680)*n^11 - (17/3072)*n^10 - (13/4608)*n^9 + (6635/9216)*n^8 - (66667/23040)*n^7 - (2096789/46080)*n^6 + (1744105/4608)*n^5 + (10251671/11520)*n^4 - (107575289/5760)*n^3 + (46056797/1440)*n^2 + (984185/3)*n - 1221248 for n>13
EXAMPLE
Some solutions for 5X5
..1..........1..........1..........0..........0..........0..........1
..0.0........0.0........1.0........0.0........1.1........0.0........0.1
..1.0.0......1.0.0......0.0.0......1.0.1......1.0.0......1.0.0......0.0.0
..0.0.0.1....1.0.0.1....1.0.0.0....0.0.0.1....0.0.0.1....0.0.0.1....0.0.0.1
..1.0.1.0.1..0.0.0.1.1..1.1.0.1.0..1.0.1.0.1..0.0.1.0.1..1.0.1.1.1..1.0.1.1.0
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin Aug 26 2011
STATUS
approved