OFFSET
1,2
COMMENTS
Equivalent to all 1s connected only in 2X2 blocks
Column 7 of A183342
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..200
FORMULA
Empirical: a(n)=a(n-1)+2*a(n-2)+18*a(n-3)+17*a(n-4)+7*a(n-5)-40*a(n-6)-78*a(n-7)-21*a(n-8)+88*a(n-9)+62*a(n-10)-49*a(n-11)-24*a(n-12)+9*a(n-13)-18*a(n-14)+2*a(n-15)+9*a(n-16)+4*a(n-17)+4*a(n-18)
EXAMPLE
Some solutions for 5X7
..0..0..0..1..1..0..0....1..1..0..0..0..0..0....0..0..0..0..1..1..0
..0..0..0..1..1..0..0....1..1..0..0..1..1..0....1..1..0..0..1..1..0
..0..0..0..0..0..1..1....0..0..0..0..1..1..0....1..1..0..0..0..0..0
..1..1..0..0..0..1..1....0..0..0..0..0..0..0....0..0..1..1..0..0..0
..1..1..0..0..0..0..0....0..0..0..0..0..0..0....0..0..1..1..0..0..0
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin Jan 04 2011
STATUS
approved