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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A252945 Number of (n+2) X (1+2) 0..2 arrays with every consecutive three elements in every row, column and nw-se diagonal having exactly two distinct values, and new values 0 upwards introduced in row major order. 1
198, 747, 2970, 11943, 48024, 193059, 776160, 3120579, 12546540, 50444415, 202816008, 815438907, 3278541276, 13181653431, 52997956416, 213082782147, 856717412004, 3444505073199, 13848925017096, 55680778531323 (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) = 6*a(n-1) - 9*a(n-2) + 4*a(n-3) + 2*a(n-4) - 6*a(n-5) + 4*a(n-6).

Empirical g.f.: 9*x*(22 - 49*x + 30*x^2 + 6*x^3 - 32*x^4 + 24*x^5) / ((1 - x)*(1 - 5*x + 4*x^2 - 2*x^4 + 4*x^5)). - Colin Barker, Dec 07 2018

EXAMPLE

Some solutions for n=4:

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

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

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

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

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

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

CROSSREFS

Column 1 of A252952.

Sequence in context: A066218 A304614 A252952 * A158222 A156771 A065697

Adjacent sequences:  A252942 A252943 A252944 * A252946 A252947 A252948

KEYWORD

nonn

AUTHOR

R. H. Hardin, Dec 25 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 July 17 18:47 EDT 2019. Contains 325109 sequences. (Running on oeis4.)