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A121360 Smallest k such that A002217(k)=n. 1
2, 1, 8, 14, 26, 62, 134, 393, 1257, 4659, 9314, 27933, 167073, 334142, 4677862, 14033577, 56134292, 2133102298, 11788191218, 52541651594 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
Least number which becomes prime or 0 or 4 after n-1 iterations of f(x) = sum of prime factors of x (cf. A001414). Agrees with A048133 except for the second term.
a(21) <= 536226160966. a(22) <= 2681130804805. a(23) <= 8512643845707. - Donovan Johnson
LINKS
CROSSREFS
Sequence in context: A102735 A088960 A263528 * A199928 A047688 A089925
KEYWORD
nonn
AUTHOR
Klaus Brockhaus, Jul 27 2006
EXTENSIONS
Edited comment and a(19)-a(20) from Donovan Johnson, Oct 16 2010
STATUS
approved

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Last modified March 29 10:22 EDT 2024. Contains 371268 sequences. (Running on oeis4.)