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A073396
The number n equals the product of two numbers: sums of prime factors of n, with and without repetition.
3
OFFSET
1,1
COMMENTS
Numbers n such that n = A008472(n)*A001414(n) (= sum of distinct prime factors of n, times sum of prime factors of n with repetition). - M. F. Hasler, May 05 2013
LINKS
Max Alekseyev, Proof of finiteness of A073396, SeqFan Mailing List, May 4, 2013.
FORMULA
a(n) = A073395(a(n)).
A073396 = { n | n = A008472(n)*A001414(n) }. - M. F. Hasler, May 05 2013
EXAMPLE
A073395(150) = A073395(2*3*5*5) = A008472(2*3*5*5)*A001414(2*3*5*5) = (2+3+5)*(2+3+5+5) = 10*15 = 150, therefore 150 is a term.
MATHEMATICA
okQ[n_] := n>1 && With[{f = FactorInteger[n]}, n == Total[Times @@@ f]* Total[f[[All, 1]]]];
Select[Range[1000], okQ] (* Jean-François Alcover, Apr 06 2021 *)
CROSSREFS
Sequence in context: A280935 A067650 A123963 * A338093 A302553 A300132
KEYWORD
nonn,full,fini,bref
AUTHOR
Reinhard Zumkeller, Jul 30 2002
EXTENSIONS
Proof that there are no further terms added by Max Alekseyev, May 04 2013
STATUS
approved