Quote:
Originally Posted by juergen
Hi all,
does anybody know a number theoretic function similar to the divisor sum, but which only sums up the divisors which are prime?
For me a function would be interesting, which builds the
1. Sum over p/x for all primes p which divide x where p<>x
or
2. Sum over p for all primes p which divide x where p<>x (the same as aove * x)
I am especially interested in Numbers x which have a Sum (1.) >= 1 in the function mentioned above (or 2. >= x). Does anybody know something about such functions or such numbers?
Thank you in advance
Juergen

Hi all,
sorry I missed something in the second form. It is wrong :o(
The first form is correct and the condition Sum (1.) >= 1.
I am trying to learn something about numbers x for which this sum is greather than x. One example is
30 <= 31
30=2*3*5
31=30/2 + 30/3 + 30/5 = 15 + 10 + 6
Does anybody know something about such numbers?
Thank you in advance
Juergen