A290141 Numbers n that have a record maximum (> n) in their aliquot sequence.

12, 18, 20, 24, 30, 102, 120, 138

Offset: 1

Author

Amiram Eldar, Jul 21 2017

Keywords

• nonn
• more

Comments

Maximum term in the aliquot sequence of n is considered only if it is larger than n.

The record values are in A290142.

Examples

			The aliquot sequence of 30 is: 30, 42, 54, 66, 78, 90, 144, 259, 45, 33, 15, 9, 4, 3, 1. The maximum is 259 which is larger than 30, and larger than the maxima of all the aliquot sequences of the numbers below 30.
		

Crossrefs

Cf. A098008, A098009, A098010, A290142.

Programs

Mathematica

g[n_] := If[n > 0, DivisorSigma[1, n] - n, 0]; f[n_] := NestWhileList[g, n, UnsameQ, All]; seq = {}; a = -1; seq = {}; Do[b = Max[Drop[f[n], 1]];  If[b > a, a = b; AppendTo[seq, n]], {n, 2, 275}]; seq (* after Robert G. Wilson v at A098009 *)