A207751 Number of nX7 0..1 arrays avoiding 0 0 1 and 0 1 1 horizontally and 0 0 1 and 1 0 0 vertically

20, 400, 2340, 9450, 51590, 247860, 1341606, 6978660, 38171520, 206898250, 1147824290, 6372877952, 35814768750, 201958261240, 1147016892780, 6537970767786, 37441623486062, 215093421143100, 1239764709916950

Offset

1,1

Comments

Column 7 of A207752

Links

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

Formula

Empirical: a(n) = 20*a(n-1) -51*a(n-2) -1431*a(n-3) +8935*a(n-4) +40417*a(n-5) -426101*a(n-6) -444083*a(n-7) +11365411*a(n-8) -4300391*a(n-9) -200417737*a(n-10) +232239905*a(n-11) +2518061713*a(n-12) -4164580427*a(n-13) -23481745867*a(n-14) +46800489827*a(n-15) +166445441485*a(n-16) -371915483333*a(n-17) -908779936543*a(n-18) +2189295925439*a(n-19) +3843112261849*a(n-20) -9750570404117*a(n-21) -12570760837627*a(n-22) +33142320325571*a(n-23) +31531972919492*a(n-24) -86008842255253*a(n-25) -59570349515902*a(n-26) +169294932682160*a(n-27) +82010381942544*a(n-28) -249200831975424*a(n-29) -77175689855936*a(n-30) +267826679018944*a(n-31) +42326080275840*a(n-32) -202109312236032*a(n-33) -4792436637696*a(n-34) +100229451300864*a(n-35) -9564035088384*a(n-36) -28820239810560*a(n-37) +5715890012160*a(n-38) +3536169467904*a(n-39) -990677827584*a(n-40) for n>41

Example

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

Crossrefs

Sequence in context: A089957 A267718 A207402 * A207127 A207948 A206938

Adjacent sequences: A207748 A207749 A207750 * A207752 A207753 A207754

Keyword

nonn

Author

R. H. Hardin Feb 19 2012

Status

approved