A346402 Decimal expansion of Sum_{k>=1} A089723(k)/2^k.

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

Offset

1,3

Comments

This constant is irrational (Golomb, 1973).

Links

Table of n, a(n) for n=1..100.

Solomon W. Golomb, A new arithmetic function of combinatorial significance, Journal of Number Theory, Vol. 5, No. 3 (1973), pp. 218-223.

Example

1.06838993007841232002084765901758238224728960865528...

Mathematica

f[n_] := DivisorSigma[0, GCD @@ FactorInteger[n][[;; , 2]]]; RealDigits[Sum[f[n]/2^n, {n, 1, 1000}], 10, 100][[1]]

Prog

(PARI) 1/2 + suminf(k=2, numdiv(gcd(factor(k)[, 2]))/2^k) \\ Michel Marcus, Jul 16 2021

Crossrefs

Cf. A089723.

Sequence in context: A316256 A054042 A184084 * A255728 A272488 A100608

Adjacent sequences: A346399 A346400 A346401 * A346403 A346404 A346405

Keyword

nonn,cons

Author

Amiram Eldar, Jul 15 2021

Status

approved