|
| |
|
|
A210167
|
|
Number of (n+1) X 2 0..3 arrays containing all values 0..3 with every 2 X 2 subblock having two or four distinct values, and new values 0..3 introduced in row major order.
|
|
1
|
|
|
|
1, 10, 101, 910, 7545, 59178, 447429, 3300982, 23953969, 171879010, 1223834045, 8668104046, 61170701289, 430597896090, 3025851581877, 21237517730278, 148936511331361, 1043880899831122, 7313575755465773, 51226014364080862
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
|
OFFSET
|
1,2
|
|
|
COMMENTS
|
|
|
|
LINKS
|
|
|
|
FORMULA
|
Empirical: a(n) = 14*a(n-1) - 55*a(n-2) + 22*a(n-3) + 132*a(n-4) + 56*a(n-5).
Empirical g.f.: x*(1 - 4*x + 16*x^2 + 24*x^3 + 8*x^4) / ((1 - 7*x)*(1 - 3*x - 2*x^2)*(1 - 4*x - 4*x^2)). - Colin Barker, Jul 15 2018
|
|
|
EXAMPLE
|
Some solutions for n=4:
..0..0....0..1....0..0....0..0....0..0....0..1....0..0....0..0....0..0....0..0
..0..1....2..3....1..0....0..1....0..1....1..0....1..0....1..0....0..1....0..1
..1..0....2..3....1..0....1..0....0..0....0..0....0..0....0..1....0..0....1..1
..2..3....1..0....0..1....0..1....1..0....2..0....2..0....0..1....0..1....0..1
..1..0....1..0....2..3....2..3....2..3....1..3....3..1....2..3....2..3....2..3
|
|
|
CROSSREFS
|
|
|
|
KEYWORD
|
nonn
|
|
|
AUTHOR
|
|
|
|
STATUS
|
approved
|
| |
|
|
