A098009 Numbers k such that the transient part of the aliquot sequence for k is finite and sets a new record.

1, 2, 4, 9, 12, 30, 102, 138

Offset

1,2

Comments

In order to extend this there is the problem that there are small numbers (276, 552, etc.) for which it is not presently known if they cycle. I propose that we assume these do not cycle, but mark the records beyond where this becomes an issue as conjectural only.

References

See references and links in A098007, A098008.

Links

Table of n, a(n) for n=1..8.

Example

138 has a transient of length 177 (see Guy's book).

Mathematica

g[n_] := If[n > 0, DivisorSigma[1, n] - n, 0]; f[n_] := NestWhileList[g, n, UnsameQ, All]; a = -1; Do[b = Length[ f[n]] - 1; If[b > a, a = b; Print[n]], {n, 275}] (* Robert G. Wilson v, Sep 10 2004 *)

Crossrefs

Records in A098008. Cf. A098010.

Sequence in context: A176472 A139557 A103690 * A129376 A266582 A227759

Adjacent sequences: A098006 A098007 A098008 * A098010 A098011 A098012

Keyword

nonn,more

Author

N. J. A. Sloane, Sep 10 2004

Extensions

102 and 138 from Robert G. Wilson v, Sep 10 2004

Status

approved