Numbers with a given prime factor sum
Problem 618
Consider the numbers 15, 16 and 18:
and .
and .
and .
15, 16 and 18 are the only numbers that have 8 as sum of the prime factors (counted with multiplicity).
and .
and .
and .
15, 16 and 18 are the only numbers that have 8 as sum of the prime factors (counted with multiplicity).
We define to be the sum of all numbers where the sum of the prime factors (with multiplicity) of is .
Hence .
Other examples: , , , .
Hence .
Other examples: , , , .
The Fibonacci sequence is , ....
Find the last nine digits of .
Find the last nine digits of .