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A059460 Iteration of unitary-sigma function: a(1) = 2, a(n) = usigma(a(n-1)). 1
2, 3, 4, 5, 6, 12, 20, 30, 72, 90, 180, 300, 520, 756, 1120, 1584, 2040, 3888, 4148, 5580, 9600, 13416, 22176, 31680, 46800, 61880, 108864, 126880, 171864, 276480, 344232, 492480, 639600, 1039584, 1663200, 2306304, 3454080, 6390144 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
LINKS
MATHEMATICA
f[n_] := Times @@ (1 + Power@@@ FactorInteger[n]); NestList[f, 2, 30] (* Amiram Eldar, Aug 11 2019 *)
CROSSREFS
Sequence in context: A032941 A273733 A218345 * A125141 A350211 A282505
KEYWORD
nonn
AUTHOR
EXTENSIONS
Corrected by Jud McCranie, Oct 28 2001
STATUS
approved

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Last modified March 28 14:21 EDT 2024. Contains 371254 sequences. (Running on oeis4.)