OFFSET
1,3
COMMENTS
Equals the square array A082771 without its first column.
FORMULA
sigma_k(n) = sum_{d|n} d^k.
EXAMPLE
The array starts in row n=1 with columns k>=1 as:
1 1 1 1 1 1 1 1
3 5 9 17 33 65 129 257
4 10 28 82 244 730 2188 6562
7 21 73 273 1057 4161 16513 65793
6 26 126 626 3126 15626 78126 390626
12 50 252 1394 8052 47450 282252 1686434
8 50 344 2402 16808 117650 823544 5764802
15 85 585 4369 33825 266305 2113665 16843009
MATHEMATICA
T[n_, k_] := DivisorSigma[k, n];
Table[T[n-k+1, k], {n, 1, 11}, {k, n, 1, -1}] // Flatten (* Jean-François Alcover, Dec 16 2021 *)
CROSSREFS
KEYWORD
AUTHOR
R. J. Mathar, Sep 16 2018
STATUS
approved