A372715 a(n) = tau(3*n-2) = A000005(3*n-2).

1, 3, 2, 4, 2, 5, 2, 4, 3, 6, 2, 4, 2, 8, 2, 4, 3, 6, 4, 4, 2, 7, 2, 8, 2, 6, 2, 4, 4, 8, 4, 4, 2, 9, 2, 4, 2, 10, 4, 4, 3, 6, 2, 8, 4, 8, 2, 4, 4, 6, 2, 8, 2, 12, 2, 4, 3, 6, 6, 4, 2, 8, 4, 8, 2, 9, 2, 4, 4, 10, 2, 4, 4, 12, 2, 4, 2, 8, 4, 8, 2, 6, 4, 8, 4, 9

Offset

1,2

Links

Table of n, a(n) for n=1..86.

Formula

Sum_{k=1..n} a(k) ~ 2*n * (log(n) + 2*gamma - 1 + 2*log(3)) / 3, where gamma is the Euler-Mascheroni constant A001620.

Mathematica

Table[DivisorSigma[0, 3*n-2], {n, 1, 150}]

Crossrefs

Cf. A372713, A372714.

Cf. A000005, A099777, A099774.

Sequence in context: A057038 A175798 A294111 * A373556 A349322 A193295

Adjacent sequences: A372712 A372713 A372714 * A372716 A372717 A372718

Keyword

nonn

Author

Vaclav Kotesovec, May 11 2024

Status

approved