A095300 Numbers n such that A094758(n) < n.

2, 6, 10, 12, 14, 18, 22, 24, 26, 30, 34, 38, 42, 46, 50, 54, 58, 60, 62, 66, 70, 74, 78, 82, 84, 86, 90, 94, 96, 98, 102, 106, 110, 114, 118, 120, 122, 126, 130, 132, 134, 138, 142, 146, 150, 154, 156, 158, 162, 166, 168, 170, 174, 178, 182, 186, 190, 194, 198, 202

Offset

1,1

Comments

The numbers of terms not exceeding 10^k, for k = 1, 2, ..., are 3, 30, 298, 2990, 29881, 298792, 2987904, 29879025, ... . Apparently, the asymptotic density of this sequence exists and equals 0.29879... . - Amiram Eldar, Jan 18 2024

Links

Amiram Eldar, Table of n, a(n) for n = 1..10000

Example

A094758(2) = 1 < 2, hence 2 is in the sequence.

Mathematica

aQ[n_] := Module[{k = 1, r = DivisorSigma[0, n]/n}, While[DivisorSigma[0, k]/k != r, k++]; k < n]; Select[Range[200], aQ] (* Amiram Eldar, Aug 19 2019 *)

Prog

(PARI) for(n=1, 205, s=numdiv(n); k=1; while(n*numdiv(k)!=k*s, k++); if(k<n, print1(n, ", ")));

Crossrefs

Cf. A000005, A094758.

Sequence in context: A139710 A194712 A057921 * A097381 A264964 A374918

Adjacent sequences: A095297 A095298 A095299 * A095301 A095302 A095303

Keyword

nonn

Author

Klaus Brockhaus, Jun 01 2004

Status

approved