A207122 Number of n X 7 0..1 arrays avoiding 0 0 1 and 0 1 0 horizontally and 0 0 1 and 0 1 1 vertically.

31, 961, 6634, 45796, 186822, 762129, 2330037, 7123561, 18090482, 45941284, 102402024, 228251664, 461670264, 933791364, 1751615118, 3285697041, 5802776793, 10248120289, 17226819610, 28957828900, 46710814150, 75347505025

Offset

1,1

Comments

Column 7 of A207123.

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
..1..1..1..0..0..0..0....1..0..1..1..0..0..0....0..1..1..0..0..0..0
..0..1..1..1..0..0..0....0..0..0..0..0..0..0....1..1..1..1..0..0..0
..1..0..0..0..0..0..0....1..0..0..0..0..0..0....0..0..0..0..0..0..0
..0..1..1..0..0..0..0....0..0..0..0..0..0..0....1..0..1..1..0..0..0

Crossrefs

Cf. A207123.

Sequence in context: A207390 A207518 A207067 * A207247 A208168 A207441

Adjacent sequences: A207119 A207120 A207121 * A207123 A207124 A207125

Keyword

nonn

Author

R. H. Hardin, Feb 15 2012

Status

approved