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!)
A240888 Number of n X 3 0..2 arrays with no element equal to a different number of vertical neighbors than horizontal neighbors, with new values 0..2 introduced in row major order. 1
2, 11, 57, 289, 1485, 7609, 38981, 199761, 1023597, 5245049, 26876501, 137719297, 705694973, 3616090505, 18529407461, 94947553233, 486525966349, 2493034391385, 12774694280053, 65459511713057, 335424674724381, 1718767975363881 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

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

FORMULA

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

Empirical g.f.: x*(2 + 5*x + 8*x^2 + 2*x^3) / (1 - 3*x - 8*x^2 - 14*x^3 - 4*x^4). - Colin Barker, Oct 29 2018

EXAMPLE

Some solutions for n=4:

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

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

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

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

CROSSREFS

Column 3 of A240893.

Sequence in context: A332524 A037490 A037570 * A120464 A164581 A054130

Adjacent sequences:  A240885 A240886 A240887 * A240889 A240890 A240891

KEYWORD

nonn

AUTHOR

R. H. Hardin, Apr 14 2014

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 11 03:12 EDT 2021. Contains 342886 sequences. (Running on oeis4.)