|
|
A291375
|
|
Irregular triangle read by rows: number of maximal irredundant sets of size k in the n-path graph.
|
|
2
|
|
|
0, 1, 0, 2, 0, 1, 1, 0, 0, 4, 0, 0, 5, 1, 0, 0, 2, 6, 0, 0, 0, 12, 1, 0, 0, 0, 8, 9, 0, 0, 0, 1, 25, 1, 0, 0, 0, 0, 28, 12, 0, 0, 0, 0, 12, 44, 1, 0, 0, 0, 0, 2, 68, 16, 0, 0, 0, 0, 0, 48, 73, 1, 0, 0, 0, 0, 0, 14, 150, 20, 0, 0, 0, 0, 0, 1, 155, 112, 1
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,4
|
|
COMMENTS
|
For each row, k lies in the range 0..ceiling(n/2). The upper end of the range is the upper irredundance number of the graph.
|
|
LINKS
|
|
|
FORMULA
|
T(n,k) = 0 for k < ceiling(n/3).
|
|
EXAMPLE
|
Triangle begins:
0, 1;
0, 2;
0, 1, 1;
0, 0, 4;
0, 0, 5, 1;
0, 0, 2, 6;
0, 0, 0, 12, 1;
0, 0, 0, 8, 9;
0, 0, 0, 1, 25, 1;
0, 0, 0, 0, 28, 12;
0, 0, 0, 0, 12, 44, 1;
0, 0, 0, 0, 2, 68, 16;
...
As polynomials these are: x; 2*x; x + x^2; 4*x^2; 5*x^2 + x^3; etc.
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn,tabf
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|