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!)
A252723 Number of (4+2) X (n+2) 0..3 arrays with every consecutive three elements in every row and diagonal having exactly two distinct values, and in every column and antidiagonal not having exactly two distinct values, and new values 0 upwards introduced in row major order. 1
84, 76, 80, 97, 112, 132, 153, 196, 224, 277, 352, 420, 513, 676, 800, 997, 1312, 1572, 1953, 2596, 3104, 3877, 5152, 6180, 7713, 10276, 12320, 15397, 20512, 24612, 30753, 40996, 49184, 61477, 81952, 98340, 122913, 163876, 196640, 245797, 327712, 393252 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
LINKS
FORMULA
Empirical: a(n) = -a(n-1) + 3*a(n-3) + 3*a(n-4) - 2*a(n-6) - 2*a(n-7) for n>8.
Empirical g.f.: x*(84 + 160*x + 156*x^2 - 75*x^3 - 271*x^4 - 224*x^5 - 78*x^6 + 42*x^7) / ((1 - x)*(1 + x)*(1 + x + x^2)*(1 - 2*x^3)). - Colin Barker, Dec 06 2018
EXAMPLE
Some solutions for n=4:
..0..0..1..0..0..1....0..0..1..0..0..2....0..1..0..0..1..0....0..1..1..2..1..1
..0..2..2..0..2..2....2..0..0..1..0..0....1..1..2..1..1..3....3..1..3..3..1..3
..0..1..0..0..1..0....3..0..3..3..0..3....2..1..1..2..1..1....1..1..0..1..1..2
..0..0..1..0..0..1....0..0..2..0..0..1....0..1..0..0..1..0....2..1..1..0..1..1
..0..3..3..0..3..3....1..0..0..2..0..0....1..1..2..1..1..2....3..1..3..3..1..3
..0..1..0..0..1..0....3..0..3..3..0..3....2..1..1..2..1..1....1..1..2..1..1..0
CROSSREFS
Row 4 of A252719.
Sequence in context: A066689 A008898 A033404 * A341304 A128873 A095607
KEYWORD
nonn
AUTHOR
R. H. Hardin, Dec 20 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 | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified March 28 05:39 EDT 2024. Contains 371235 sequences. (Running on oeis4.)