A351749 a(n) = Sum_{p|n, p prime} sigma_p(p).

0, 5, 28, 5, 3126, 33, 823544, 5, 28, 3131, 285311670612, 33, 302875106592254, 823549, 3154, 5, 827240261886336764178, 33, 1978419655660313589123980, 3131, 823572, 285311670617, 20880467999847912034355032910568, 33, 3126, 302875106592259

Offset

1,2

Links

Table of n, a(n) for n=1..26.

Formula

a(p^k) = p^p + 1, for p prime and k >= 1.

Example

a(6) = 33; a(6) = Sum_{p|6, p prime} sigma_p(p) = sigma_2(2) + sigma_3(3) = (1^2 + 2^2) + (1^3 + 3^3) = 33.

Crossrefs

Cf. A023887 (sigma_n(n)).

Sequence in context: A063860 A000878 A052470 * A016087 A347251 A321236

Adjacent sequences: A351746 A351747 A351748 * A351750 A351751 A351752

Keyword

nonn

Author

Wesley Ivan Hurt, Feb 17 2022

Status

approved