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!)
A209729 1/4 the number of (n+1) X 2 0..3 arrays with every 2 X 2 subblock having distinct edge sums. 1
22, 124, 696, 3912, 21976, 123480, 693752, 3897880, 21900088, 123045592, 691329528, 3884227224, 21823477432, 122614931544, 688910387576, 3870634114072, 21747107494456, 122185841630680, 686499566270712 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 1 of A209736.

LINKS

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

FORMULA

Empirical: a(n) = 3*a(n-1) + 14*a(n-2) + 4*a(n-3).

Empirical g.f.: 2*x*(11 + 29*x + 8*x^2) / (1 - 3*x - 14*x^2 - 4*x^3). - Colin Barker, Jul 12 2018

EXAMPLE

Some solutions for n=4:

..3..1....1..0....1..2....1..3....1..2....0..0....2..1....1..3....1..0....1..1

..2..0....1..3....0..2....0..2....3..3....1..2....2..0....0..2....1..3....3..2

..1..0....2..3....3..2....3..2....1..2....1..3....1..0....3..2....0..2....0..0

..1..3....1..1....3..0....1..0....0..0....0..2....1..3....3..0....1..2....3..1

..0..2....0..3....2..0....1..3....1..3....0..1....2..3....3..1....1..3....2..0

CROSSREFS

Cf. A209736.

Sequence in context: A247701 A039439 A209736 * A252835 A220622 A229375

Adjacent sequences:  A209726 A209727 A209728 * A209730 A209731 A209732

KEYWORD

nonn

AUTHOR

R. H. Hardin, Mar 12 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 August 16 05:55 EDT 2022. Contains 356160 sequences. (Running on oeis4.)