OFFSET
1,1
COMMENTS
Column 1 of A231957
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 4*a(n-1) -2*a(n-2) +4*a(n-3)
EXAMPLE
Some solutions for n=7
..0..0....0..0....0..0....0..0....0..0....0..0....0..0....0..0....0..1....0..1
..0..0....0..0....1..0....0..1....0..0....0..1....0..1....1..0....1..0....0..1
..0..1....0..0....1..0....1..0....0..0....0..1....1..1....1..1....0..1....0..0
..0..1....1..0....1..0....1..0....1..0....0..0....0..1....0..1....0..1....1..0
..1..1....0..1....0..0....1..0....0..1....0..0....0..1....0..1....1..0....0..1
..0..1....1..0....0..1....0..1....0..1....1..1....1..0....1..1....0..0....0..1
..1..0....0..1....1..1....1..0....1..0....0..1....1..0....0..0....1..0....1..0
..0..1....1..1....0..0....0..0....0..0....0..1....0..1....1..1....1..0....0..0
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Nov 15 2013
STATUS
approved