A378914 Smallest positive m such that sigma(m) does not divide n, where sigma is the sum-of-divisors function (A000203).

2, 2, 3, 2, 2, 3, 2, 2, 3, 2, 2, 4, 2, 2, 3, 2, 2, 3, 2, 2, 3, 2, 2, 4, 2, 2, 3, 2, 2, 3, 2, 2, 3, 2, 2, 4, 2, 2, 3, 2, 2, 3, 2, 2, 3, 2, 2, 4, 2, 2, 3, 2, 2, 3, 2, 2, 3, 2, 2, 4, 2, 2, 3, 2, 2, 3, 2, 2, 3, 2, 2, 4, 2, 2, 3, 2, 2, 3, 2, 2, 3, 2, 2, 7, 2, 2, 3, 2, 2, 3

Offset

1,1

Links

Paolo Xausa, Table of n, a(n) for n = 1..10000

Index entries for sequences related to sigma(n)

Mathematica

A378914[n_] := Module[{m = 1}, While[Divisible[n, DivisorSigma[1, ++m]]]; m];
Array[A378914, 100]

Prog

(PARI) a(n) = my(m=1); while (!(n % sigma(m)), m++); m; \\ Michel Marcus, Dec 11 2024

Crossrefs

Cf. A000203, A051549, A378912.

Sequence in context: A003589 A361486 A082204 * A152727 A087159 A366922

Adjacent sequences: A378911 A378912 A378913 * A378915 A378919 A378920

Keyword

nonn,easy,new

Author

Paolo Xausa, Dec 11 2024

Status

approved