A372788 a(n) = tau(8*n) = A000005(8*n).

4, 5, 8, 6, 8, 10, 8, 7, 12, 10, 8, 12, 8, 10, 16, 8, 8, 15, 8, 12, 16, 10, 8, 14, 12, 10, 16, 12, 8, 20, 8, 9, 16, 10, 16, 18, 8, 10, 16, 14, 8, 20, 8, 12, 24, 10, 8, 16, 12, 15, 16, 12, 8, 20, 16, 14, 16, 10, 8, 24, 8, 10, 24, 10, 16, 20, 8, 12, 16, 20, 8, 21

Offset: 1

Author

Vaclav Kotesovec, May 13 2024

Keywords

• nonn

Links

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

Crossrefs

Cf. A283122.

Cf. A000005, A099777, A372713, A372784, A372785, A372786, A372787, A372789, A372790, A372791, A372792.

Programs

Mathematica

Table[DivisorSigma[0, 8*n], {n, 1, 150}]

Formula

Sum_{k=1..n} a(k) ~ (20*n*(log(n) + 2*gamma - 1) + n*12*log(2)) / 8, where gamma is the Euler-Mascheroni constant A001620.