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A290141 Numbers n that have a record maximum (> n) in their aliquot sequence. 1
12, 18, 20, 24, 30, 102, 120, 138 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

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

The record values are in A290142.

LINKS

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

EXAMPLE

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.

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 *)

CROSSREFS

Cf. A098008, A098009, A098010, A290142.

Sequence in context: A005101 A124626 A231547 * A087245 A153501 A215012

Adjacent sequences:  A290138 A290139 A290140 * A290142 A290143 A290144

KEYWORD

nonn,more

AUTHOR

Amiram Eldar, Jul 21 2017

STATUS

approved

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Last modified March 25 21:57 EDT 2019. Contains 321477 sequences. (Running on oeis4.)