A180366 Numbers k such that 0 < A000203(k)-k-1 < k.

4, 6, 8, 9, 10, 14, 15, 16, 21, 22, 25, 26, 27, 28, 32, 33, 34, 35, 38, 39, 44, 45, 46, 49, 50, 51, 52, 55, 57, 58, 62, 63, 64, 65, 68, 69, 74, 75, 76, 77, 81, 82, 85, 86, 87, 91, 92, 93, 94, 95, 98, 99, 105, 106, 110, 111, 115, 116, 117, 118, 119, 121, 122, 123, 124, 125, 128, 129

Offset

1,1

Links

Table of n, a(n) for n=1..68.

Formula

(A005100 U A000396) INTERSECT A002808. - R. J. Mathar, Sep 25 2010

Mathematica

Select[Range[130], CompositeQ[#] && DivisorSigma[-1, #] <= 2 &] (* Amiram Eldar, Mar 18 2024 *)

Crossrefs

Cf. A000203, A000396, A002808, A005100.

Sequence in context: A071941 A188654 A330991 * A340656 A373482 A346041

Adjacent sequences: A180363 A180364 A180365 * A180367 A180368 A180369

Keyword

nonn

Author

Alexey Galkin (fetch91(AT)gmail.com), Sep 09 2010

Extensions

Corrected (4, 16 inserted) by R. J. Mathar, Sep 25 2010

Status

approved