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A055020 Number of iterations of sigma() required until 2n (or greater) is reached. 1
2, 2, 2, 2, 1, 2, 2, 3, 2, 2, 1, 3, 2, 2, 2, 2, 1, 2, 1, 2, 2, 2, 1, 3, 2, 2, 1, 2, 1, 2, 2, 2, 2, 2, 1, 3, 2, 2, 1, 2, 1, 3, 2, 2, 2, 2, 1, 3, 2, 2, 2, 2, 1, 2, 1, 2, 2, 2, 1, 3, 2, 2, 2, 2, 1, 3, 2, 2, 1, 2, 1, 3, 2, 2, 2, 2, 1, 2, 1, 4, 2, 2, 1, 2, 2, 2, 1, 2, 1, 2, 2, 2, 2, 2, 1, 3, 2, 2, 1, 2, 1, 2, 1 (list; graph; refs; listen; history; text; internal format)
OFFSET

2,1

LINKS

Table of n, a(n) for n=2..104.

EXAMPLE

sigma(sigma(sigma(9)))=24 >= 2*9, so a(9)=3.

CROSSREFS

Cf. A000203, A055021.

Sequence in context: A063982 A318882 A327160 * A052435 A094701 A210452

Adjacent sequences:  A055017 A055018 A055019 * A055021 A055022 A055023

KEYWORD

nonn

AUTHOR

Jud McCranie, May 31 2000

STATUS

approved

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Last modified October 20 17:50 EDT 2019. Contains 328268 sequences. (Running on oeis4.)