login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A208072 Number of 7Xn 0..1 arrays avoiding 0 0 0 and 1 1 1 horizontally and 0 0 1 and 0 1 1 vertically 1
20, 400, 432, 2688, 11424, 44064, 198000, 844800, 3542544, 15213984, 64859616, 275633280, 1175819856, 5010674496, 21340192176, 90942560256, 387500834976, 1650940063776, 7034502996720, 29972774288640, 127706156346384 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Row 7 of A208069

LINKS

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

FORMULA

Empirical: a(n) = a(n-1) +4*a(n-2) +39*a(n-3) +20*a(n-4) +19*a(n-5) -191*a(n-6) -42*a(n-7) -36*a(n-8) +216*a(n-9) for n>11

EXAMPLE

Some solutions for n=4

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

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

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

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

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

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

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

CROSSREFS

Sequence in context: A158534 A171325 A075843 * A208122 A207372 A208017

Adjacent sequences:  A208069 A208070 A208071 * A208073 A208074 A208075

KEYWORD

nonn

AUTHOR

R. H. Hardin Feb 23 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.

License Agreements, Terms of Use, Privacy Policy. .

Last modified November 18 14:59 EST 2019. Contains 329262 sequences. (Running on oeis4.)