A290142 Records of the maxima of the aliquot sequences of the numbers in A290141.

16, 21, 22, 55, 259, 759, 32571, 179931895322

Offset

1,1

Comments

a(8) was calculated by D. H. Lehmer.

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]; rec = {}; a = -1; seq = {}; Do[b = Max[Drop[f[n], 1]];
If[b > a, a = b; AppendTo[rec, b]], {n, 2, 275}] ; rec (* after Robert G. Wilson v at A098009 *)

Crossrefs

Cf. A008888, A098008, A098009, A098010, A290141.

Sequence in context: A070573 A186462 A205098 * A165160 A180411 A050436

Adjacent sequences: A290139 A290140 A290141 * A290143 A290144 A290145

Keyword

nonn,more

Author

Amiram Eldar, Jul 21 2017

Status

approved