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A081758 Sum of prime factors (with repetition) of sum of prime factors (with repetition) of n. 2
2, 3, 4, 5, 5, 7, 5, 5, 7, 11, 7, 13, 6, 6, 6, 17, 6, 19, 6, 7, 13, 23, 6, 7, 8, 6, 11, 29, 7, 31, 7, 9, 19, 7, 7, 37, 10, 8, 11, 41, 7, 43, 8, 11, 10, 47, 11, 9, 7, 9, 17, 53, 11, 8, 13, 13, 31, 59, 7, 61, 14, 13, 7, 8, 8, 67, 10, 15, 9, 71, 7, 73, 16, 13, 23, 8, 8, 79, 13, 7, 43, 83, 9, 13, 11 (list; graph; refs; listen; history; text; internal format)
OFFSET
2,1
COMMENTS
a(n) = A001414(A001414(n)). For further iterations see: A029908, A002217;
a(n)=n iff n is prime or 4.
LINKS
EXAMPLE
18 = 2*3*3 -> 2+3+3 = 2*2*2 -> 2+2+2 = 6: a(18) = 6.
CROSSREFS
Sequence in context: A345303 A345310 A029908 * A106492 A338038 A112264
KEYWORD
nonn
AUTHOR
Reinhard Zumkeller, Apr 08 2003
STATUS
approved

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Last modified March 28 11:44 EDT 2024. Contains 371241 sequences. (Running on oeis4.)