A372787 a(n) = tau(7*n) = A000005(7*n).

2, 4, 4, 6, 4, 8, 3, 8, 6, 8, 4, 12, 4, 6, 8, 10, 4, 12, 4, 12, 6, 8, 4, 16, 6, 8, 8, 9, 4, 16, 4, 12, 8, 8, 6, 18, 4, 8, 8, 16, 4, 12, 4, 12, 12, 8, 4, 20, 4, 12, 8, 12, 4, 16, 8, 12, 8, 8, 4, 24, 4, 8, 9, 14, 8, 16, 4, 12, 8, 12, 4, 24, 4, 8, 12, 12, 6, 16, 4

Offset

1,1

Links

Table of n, a(n) for n=1..79.

Vaclav Kotesovec, Graph - the asymptotic ratio (100000 terms)

Formula

Sum_{k=1..n} a(k) ~ (13*n*(log(n) + 2*gamma - 1) + n*log(7)) / 7, where gamma is the Euler-Mascheroni constant A001620.

Mathematica

Table[DivisorSigma[0, 7*n], {n, 1, 150}]

Crossrefs

Cf. A283078.

Cf. A000005, A099777, A372713, A372784, A372785, A372786, A372788, A372789, A372790, A372791, A372792.

Sequence in context: A372785 A091666 A084290 * A372791 A062011 A225520

Adjacent sequences: A372784 A372785 A372786 * A372788 A372789 A372790

Keyword

nonn

Author

Vaclav Kotesovec, May 13 2024

Status

approved