login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A209547 1/4 the number of (n+1)X3 0..3 arrays with every 2X2 subblock having exactly two distinct clockwise edge differences 1
20, 105, 562, 3051, 16582, 90186, 490547, 2668340, 14514612, 78953457, 429474356, 2336164666, 12707780399, 69125130364, 376012453568, 2045354053809, 11125890031368, 60520294171670, 329205663240431, 1790744248612872 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 2 of A209553

LINKS

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

Index entries for linear recurrences with constant coefficients, signature (8,-14,-3,20,-8,-2).

FORMULA

Empirical: a(n) = 8*a(n-1) -14*a(n-2) -3*a(n-3) +20*a(n-4) -8*a(n-5) -2*a(n-6)

EXAMPLE

Some solutions for n=4

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

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

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

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

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

MATHEMATICA

LinearRecurrence[{8, -14, -3, 20, -8, -2}, {20, 105, 562, 3051, 16582, 90186}, 30] (* Harvey P. Dale, Mar 11 2015 *)

CROSSREFS

Sequence in context: A181703 A187756 A248087 * A278642 A135174 A173963

Adjacent sequences:  A209544 A209545 A209546 * A209548 A209549 A209550

KEYWORD

nonn

AUTHOR

R. H. Hardin Mar 10 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 April 4 07:32 EDT 2020. Contains 333213 sequences. (Running on oeis4.)