|
|
A364228
|
|
Triangle read by rows: T(n, k) is the number of n X n Hermitian Toeplitz matrices of rank k using all the integers 1, 2, ..., n and with all off-diagonal elements purely imaginary.
|
|
1
|
|
|
1, 0, 2, 0, 1, 5, 0, 0, 0, 24, 0, 0, 0, 0, 120, 0, 0, 0, 0, 1, 719, 0, 0, 0, 0, 0, 0, 5040, 0, 0, 0, 0, 0, 2, 1, 40317, 0, 0, 0, 0, 0, 0, 0, 6, 362874, 0, 0, 0, 0, 0, 0, 1, 0, 1, 3628798
(list;
table;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,3
|
|
LINKS
|
|
|
EXAMPLE
|
The triangle begins:
1;
0, 2;
0, 1, 5;
0, 0, 0, 24;
0, 0, 0, 0, 120;
0, 0, 0, 0, 1, 719;
0, 0, 0, 0, 0, 0, 5040;
0, 0, 0, 0, 0, 2, 1, 40317;
0, 0, 0, 0, 0, 0, 0, 6, 362874;
0, 0, 0, 0, 0, 0, 1, 0, 1, 3628798;
...
|
|
MATHEMATICA
|
T[n_, k_]:=Count[Flatten[Table[MatrixRank[ToeplitzMatrix[Join[{d}, I Part[Permutations[Drop[Range[n], {d}]], i]]]], {i, (n-1)!}, {d, n}]], k]; Table[T[n, k], {n, 9}, {k, n}]//Flatten
|
|
CROSSREFS
|
|
|
KEYWORD
|
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|