A207767 Number of 7Xn 0..1 arrays avoiding 0 0 0 and 1 0 1 horizontally and 0 1 1 and 1 0 1 vertically.

31, 961, 2305, 17563, 67330, 178627, 887114, 3733566, 11979209, 49800326, 208738438, 742476229, 2900533473, 11843654162, 44397947317, 170655647841, 681016789541, 2614418854083, 10044216333681, 39503065976101

Offset: 1

Author

R. H. Hardin Feb 19 2012

Keywords

• nonn

Comments

Row 7 of A207762

Examples

			Some solutions for n=4
..0..0..1..1....1..1..0..0....0..1..0..0....1..1..1..1....1..1..0..0
..1..0..0..1....0..1..0..0....0..1..1..1....1..0..0..1....0..1..1..0
..0..1..0..0....0..0..1..0....0..1..0..0....1..0..0..1....0..1..0..0
..0..0..1..0....1..0..0..1....0..1..0..0....0..1..0..0....0..1..0..0
..1..0..0..1....0..1..0..0....1..0..0..1....0..0..1..0....0..1..0..0
..0..1..0..0....0..0..1..0....0..0..1..0....1..0..0..1....1..0..0..1
..0..0..1..0....1..0..0..1....0..1..0..0....0..1..0..0....0..0..1..0
		

Links

• R. H. Hardin, Table of n, a(n) for n = 1..210

Formula

Empirical: a(n) = 3*a(n-1) -3*a(n-2) +75*a(n-3) -165*a(n-4) +117*a(n-5) -1993*a(n-6) +3819*a(n-7) -1872*a(n-8) +28120*a(n-9) -52719*a(n-10) +21633*a(n-11) -245836*a(n-12) +475386*a(n-13) -202047*a(n-14) +1424731*a(n-15) -2854572*a(n-16) +1336596*a(n-17) -5595456*a(n-18) [phone]*a(n-19) -5756664*a(n-20) [phone]*a(n-21) -30146304*a(n-22) [phone]*a(n-23) -25534368*a(n-24) [phone]*a(n-25) -27030768*a(n-26) [phone]*a(n-27) -53527680*a(n-28) [phone]*a(n-29) -16039296*a(n-30) [phone]*a(n-31) -15780096*a(n-32) +3960576*a(n-33) -7464960*a(n-34) +3732480*a(n-35) for n>37