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A319278 Square array sigma_k(n) read down antidiagonals: sum of the k-th powers of the divisors of n. 1
1, 1, 3, 1, 5, 4, 1, 9, 10, 7, 1, 17, 28, 21, 6, 1, 33, 82, 73, 26, 12, 1, 65, 244, 273, 126, 50, 8, 1, 129, 730, 1057, 626, 252, 50, 15, 1, 257, 2188, 4161, 3126, 1394, 344, 85, 13, 1, 513, 6562, 16513, 15626, 8052, 2402, 585, 91, 18, 1, 1025, 19684, 65793, 78126, 47450, 16808, 4369, 757, 130, 12 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

1,3

COMMENTS

Equals the square array A082771 without its first column.

LINKS

Table of n, a(n) for n=1..66.

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

CROSSREFS

Columns: A000203, A001157, A001158, A001159.

Rows: A000012, A000051, A034472, A001576, A034474, A034488.

Cf. A082771, A023887 (diagonal), A319194 (partial column sums).

Sequence in context: A029655 A110813 A124883 * A294579 A308502 A308674

Adjacent sequences:  A319275 A319276 A319277 * A319279 A319280 A319281

KEYWORD

nonn,tabl,easy

AUTHOR

R. J. Mathar, Sep 16 2018

STATUS

approved

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Last modified December 9 08:13 EST 2021. Contains 349627 sequences. (Running on oeis4.)