A379769 a(n) = (A006218(n) mod n).

0, 1, 2, 0, 0, 2, 2, 4, 5, 7, 7, 11, 11, 13, 0, 2, 1, 4, 3, 6, 7, 8, 7, 12, 12, 13, 14, 17, 16, 21, 20, 23, 24, 25, 26, 32, 31, 32, 33, 38, 37, 0, 41, 0, 2, 2, 0, 6, 5, 7, 7, 9, 7, 11, 11, 15, 15, 15, 13, 21, 19, 19, 21, 24, 24, 28, 26, 28, 28, 32, 30, 38, 36, 36, 38, 40, 40, 44

Offset

1,3

Links

Table of n, a(n) for n=1..78.

Formula

a(A050226(k)) = 0.

Example

n = 7: a(7) = A006218(7) mod 7 = 2.

Mathematica

With[{nmax = 100}, Mod[Accumulate[DivisorSigma[0, Range[nmax]]], Range[nmax]]] (* Amiram Eldar, Jan 06 2025 *)

Prog

(PARI) a(n) = sum(k=1, n, numdiv(k)) % n; \\ Michel Marcus, Jan 06 2025

Crossrefs

Cf. A006218, A050226.

Sequence in context: A033718 A033737 A033747 * A087611 A282133 A338819

Adjacent sequences: A379766 A379767 A379768 * A379770 A379771 A379772

Keyword

nonn,look

Author

Ctibor O. Zizka, Jan 06 2025

Status

approved