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A047826 Becomes prime after exactly 7 iterations of f(x) = sum of prime factors of x. 0
1774, 2566, 3548, 4497, 5132, 6382, 6843, 7096, 7538, 8043, 8882, 8902, 9003, 9286, 10264, 10334, 10862, 10997, 11019, 11162, 11469, 11490, 12009, 12226, 12442, 12507, 12764, 12817, 12842, 13215, 13491, 13849, 13947, 14192, 14642, 14677 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

f(x) = sum of prime factors without multiplicity, so that f(1500) = 2+3+5 = 10.

LINKS

Table of n, a(n) for n=1..36.

CROSSREFS

Sequence in context: A176478 A187132 A185836 * A143995 A205938 A238307

Adjacent sequences:  A047823 A047824 A047825 * A047827 A047828 A047829

KEYWORD

nonn

AUTHOR

David W. Wilson

STATUS

approved

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Last modified September 24 23:43 EDT 2022. Contains 356951 sequences. (Running on oeis4.)