|
| |
|
|
A232509
|
|
Number of (n+1)X(2+1) 0..2 arrays with every element next to itself plus and minus one within the range 0..2 horizontally, diagonally or antidiagonally, with no adjacent elements equal
|
|
1
|
|
|
|
16, 52, 200, 784, 3052, 11900, 46432, 181184, 707044, 2759212, 10767816, 42021520, 163989692, 639972924, 2497507216, 9746573088, 38036202612, 148437067820, 579278732344, 2260647259184, 8822222791628, 34428907339516, 134359524664384
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
|
OFFSET
|
1,1
|
|
|
COMMENTS
|
|
|
|
LINKS
|
|
|
|
FORMULA
|
Empirical: a(n) = 4*a(n-1) +a(n-2) -4*a(n-3) -5*a(n-4) -2*a(n-5) +a(n-6) +2*a(n-7).
Empirical: G.f.: -4*x*(4-3*x-6*x^2-x^3+x^4+x^6) / ( -1+4*x+x^2-4*x^3-5*x^4-2*x^5+x^6+2*x^7 ). - R. J. Mathar, Nov 23 2014
|
|
|
EXAMPLE
|
Some solutions for n=7
..2..1..2....0..1..2....2..1..0....0..1..0....0..1..0....2..1..2....2..1..2
..2..1..0....2..1..0....2..1..0....2..1..0....2..1..2....0..1..2....0..1..0
..2..1..0....0..1..2....0..1..0....0..1..2....2..1..0....0..1..0....0..1..2
..2..1..0....0..1..2....2..1..0....2..1..0....2..1..0....2..1..0....0..1..0
..0..1..0....2..1..2....2..1..0....0..1..0....2..1..2....0..1..2....0..1..2
..0..1..2....2..1..0....0..1..0....2..1..0....2..1..2....0..1..2....2..1..0
..0..1..0....0..1..2....0..1..2....2..1..0....2..1..0....2..1..2....2..1..0
..0..1..2....2..1..2....0..1..2....2..1..2....2..1..0....0..1..2....2..1..2
|
|
|
CROSSREFS
|
|
|
|
KEYWORD
|
nonn
|
|
|
AUTHOR
|
|
|
|
STATUS
|
approved
|
| |
|
|
