A208146 Number of 7Xn 0..1 arrays avoiding 0 0 1 and 0 1 1 horizontally and 0 0 1 and 1 0 1 vertically

14, 196, 1176, 7056, 28224, 112896, 352800, 1102500, 2910600, 7683984, 17929296, 41835024, 88792704, 188457984, 371026656, 730458729, 1352701350, 2505002500, 4408804400, 7759495744, 13082125056, 22055814144, 35840697984, 58241134224

Offset

1,1

Comments

Row 7 of A208142

Links

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

Formula

Empirical: a(n) = 2*a(n-1) +12*a(n-2) -26*a(n-3) -65*a(n-4) +156*a(n-5) +208*a(n-6) -572*a(n-7) -429*a(n-8) +1430*a(n-9) +572*a(n-10) -2574*a(n-11) -429*a(n-12) +3432*a(n-13) -3432*a(n-15) +429*a(n-16) +2574*a(n-17) -572*a(n-18) -1430*a(n-19) +429*a(n-20) +572*a(n-21) -208*a(n-22) -156*a(n-23) +65*a(n-24) +26*a(n-25) -12*a(n-26) -2*a(n-27) +a(n-28)

Example

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

Crossrefs

Sequence in context: A207445 A207429 A208371 * A207743 A207720 A171288

Adjacent sequences: A208143 A208144 A208145 * A208147 A208148 A208149

Keyword

nonn

Author

R. H. Hardin Feb 23 2012

Status

approved