A372790 a(n) = tau(10*n) = A000005(10*n).

4, 6, 8, 8, 6, 12, 8, 10, 12, 9, 8, 16, 8, 12, 12, 12, 8, 18, 8, 12, 16, 12, 8, 20, 8, 12, 16, 16, 8, 18, 8, 14, 16, 12, 12, 24, 8, 12, 16, 15, 8, 24, 8, 16, 18, 12, 8, 24, 12, 12, 16, 16, 8, 24, 12, 20, 16, 12, 8, 24, 8, 12, 24, 16, 12, 24, 8, 16, 16, 18, 8, 30

Offset

1,1

Links

Table of n, a(n) for n=1..72.

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

Formula

Sum_{k=1..n} a(k) ~ (27*n*(log(n) + 2*gamma - 1) + n*(9*log(2) + 3*log(5))) / 10, where gamma is the Euler-Mascheroni constant A001620.

Mathematica

Table[DivisorSigma[0, 10*n], {n, 1, 150}]

Crossrefs

Cf. A000005, A099777, A372713, A372784, A372785, A372786, A372787, A372788, A372789, A372791, A372792.

Sequence in context: A352421 A159576 A199626 * A163639 A196355 A095253

Adjacent sequences: A372787 A372788 A372789 * A372791 A372792 A372793

Keyword

nonn

Author

Vaclav Kotesovec, May 13 2024

Status

approved