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

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A206872 Number of 3 X n 0..1 arrays avoiding 0 0 0 horizontally and 1 0 1 vertically. 2
 7, 49, 211, 1153, 6139, 31529, 165783, 867545, 4529439, 23698777, 123917699, 647878921, 3387923179, 17715041713, 92629806615, 484357042545, 2532662234303, 13243089222385, 69247131747475, 362087861614577, 1893329530949883 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Row 3 of A206871. LINKS R. H. Hardin, Table of n, a(n) for n = 1..210 FORMULA Empirical: a(n) = 3*a(n-1) + 7*a(n-2) + 27*a(n-3) - 13*a(n-4) + a(n-5) - 31*a(n-6) + 5*a(n-7) - 2*a(n-8) + 4*a(n-9). Empirical g.f.: x*(7 + 28*x + 15*x^2 - 12*x^3 - 29*x^4 - 26*x^5 + 3*x^6 + 2*x^7 + 4*x^8) / ((1 - x)*(1 - 2*x - 9*x^2 - 36*x^3 - 23*x^4 - 24*x^5 + 7*x^6 + 2*x^7 + 4*x^8)). - Colin Barker, Mar 04 2018 EXAMPLE Some solutions for n=4: ..1..1..1..1....0..1..0..0....1..0..0..1....0..0..1..0....0..0..1..0 ..1..1..1..1....1..1..0..0....0..1..0..0....1..0..1..0....0..0..1..1 ..1..1..1..1....0..1..1..0....0..0..1..0....0..1..0..0....1..0..0..1 CROSSREFS Cf. A206871. Sequence in context: A188608 A188601 A206866 * A133047 A223639 A188689 Adjacent sequences:  A206869 A206870 A206871 * A206873 A206874 A206875 KEYWORD nonn AUTHOR R. H. Hardin, Feb 13 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 | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified January 24 18:53 EST 2022. Contains 350565 sequences. (Running on oeis4.)