A358658 Decimal expansion of the asymptotic mean of the e-unitary Euler function (A321167).

1, 3, 0, 7, 3, 2, 1, 3, 7, 1, 7, 0, 6, 0, 7, 2, 3, 6, 9, 2, 9, 6, 4, 2, 2, 8, 0, 4, 2, 5, 3, 9, 8, 8, 3, 9, 1, 4, 2, 7, 4, 3, 4, 6, 8, 6, 0, 8, 2, 3, 9, 4, 0, 9, 8, 0, 1, 5, 3, 6, 3, 5, 6, 9, 8, 1, 7, 0, 0, 9, 7, 0, 8, 9, 0, 0, 8, 4, 9, 7, 3, 2, 2, 0, 0, 7, 2, 0, 2, 5, 4, 0, 4, 5, 4, 8, 4, 4, 8, 1, 2, 9, 7, 2, 9

Offset

1,2

Links

Table of n, a(n) for n=1..105.

Nicusor Minculete and László Tóth, Exponential unitary divisors, Annales Univ. Sci. Budapest., Sect. Comp. Vol. 35 (2011), pp. 205-216.

Formula

Equals lim_{m->oo} (1/m) Sum_{k=1..m} A321167(k).

Equals Product_{p prime} (1 + Sum_{e >= 3} (uphi(e) - uphi(e-1))/p^e), where uphi is the unitary totient function (A047994).

Example

1.307321371706072369296422804253988391427434686082394...

Mathematica

f[p_, e_] := p^e - 1; uphi[1] = 1; uphi[n_] := Times @@ f @@@ FactorInteger[n]; $MaxExtraPrecision = 500; m = 500; fun[x_] := Log[1 + Sum[x^e*(uphi[e] - uphi[e - 1]), {e, 3, m}]]; c = Rest[CoefficientList[Series[fun[x], {x, 0, m}], x]*Range[0, m]]; RealDigits[Exp[fun[1/2] + NSum[Indexed[c, k]*(PrimeZetaP[k] - 1/2^k)/k, {k, 2, m}, NSumTerms -> m, WorkingPrecision -> m]], 10, 100][[1]]

Crossrefs

Cf. A047994, A321167, A327838.

Sequence in context: A298095 A327803 A199667 * A181163 A363392 A098867

Adjacent sequences: A358655 A358656 A358657 * A358659 A358660 A358661

Keyword

nonn,cons

Author

Amiram Eldar, Nov 25 2022

Status

approved