login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A208779 Number of n X 7 0..1 arrays avoiding 0 0 0 and 0 0 1 horizontally and 0 1 1 and 1 1 1 vertically. 1
42, 1764, 252, 420, 672, 1092, 1764, 2856, 4620, 7476, 12096, 19572, 31668, 51240, 82908, 134148, 217056, 351204, 568260, 919464, 1487724, 2407188, 3894912, 6302100, 10197012, 16499112, 26696124, 43195236, 69891360, 113086596 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
Column 7 of A208780.
LINKS
FORMULA
Empirical: a(n) = a(n-1) + a(n-2) for n>4.
Empirical g.f.: 42*x*(1 + 41*x - 37*x^2 - 38*x^3) / (1 - x - x^2). - Colin Barker, Jul 06 2018
EXAMPLE
Some solutions for n=4:
..1..0..1..0..1..0..1....1..1..1..0..1..0..0....1..1..0..1..0..1..0
..0..1..0..1..0..1..1....1..0..1..0..1..0..0....1..0..1..0..1..0..1
..1..0..1..0..1..0..0....0..1..0..1..0..1..1....0..1..0..1..0..1..0
..0..1..0..1..0..1..1....1..0..1..0..1..0..0....1..0..1..0..1..0..1
CROSSREFS
Cf. A208780.
Sequence in context: A170761 A218744 A158727 * A208500 A207588 A207844
KEYWORD
nonn
AUTHOR
R. H. Hardin, Mar 01 2012
STATUS
approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified February 25 17:53 EST 2024. Contains 370332 sequences. (Running on oeis4.)