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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A228734 Number of arrays of the median of three adjacent elements of some length n+2 0..2 array. 1
3, 9, 27, 77, 185, 447, 1071, 2593, 6333, 15513, 38039, 93213, 228279, 558849, 1367945, 3348489, 8196847, 20065943, 49122291, 120253773, 294386457, 720668887, 1764221329, 4318870217, 10572732933, 25882394413, 63360952825, 155109705901 (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) -a(n-2) -2*a(n-3) +a(n-4) +5*a(n-5) -2*a(n-6) +a(n-7) +a(n-9) +a(n-10) -2*a(n-12) -a(n-13) +a(n-14)

EXAMPLE

Some solutions for n=4

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

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

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

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

CROSSREFS

Column 2 of A228740.

Sequence in context: A289693 A269684 A182897 * A048481 A269488 A027027

Adjacent sequences:  A228731 A228732 A228733 * A228735 A228736 A228737

KEYWORD

nonn

AUTHOR

R. H. Hardin Sep 01 2013

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 February 20 06:26 EST 2019. Contains 320332 sequences. (Running on oeis4.)