Problem 45429. Prime Sum
What is the minimum value that can be written as sum of primes in n different ways?
For example, 10 is the minimum value that can be written as the sum of primes in exactly five different ways:
2 + 2 + 2 + 2 + 2 2 + 2 + 3 + 3 2 + 3 + 5 5 + 5 3 +7
8 can be written in 3 different ways but 7 can also be written in 3 different ways. So 7 is the right answer.
Solution Stats
Problem Comments
-
3 Comments
what are the three ways to obtain 7 by summing primes?! 2+5, 2+2+3, and?
Found at a blog that if a number is prime, wrongly some people consider this a sum. So the third way to obtain 7 would be 7 by itself, which is wrong, because it should actually be 7+0, but 0 is not a prime (and 7 by itself is not a sum). https://medium.com/@yevgeniy.v.filatov/counting-the-ways-to-express-a-number-as-a-sum-of-primes-e5e871b48193#:~:text=For%20the%20number%207%20we,as%20a%20sum%20of%20primes.
Maybe it's more precise to say partitions instead of a sum. In any case, solving CP 1240 helps here as well.
Solution Comments
Show commentsProblem Recent Solvers7
Suggested Problems
-
400 Solvers
-
371 Solvers
-
508 Solvers
-
Change the sign of even index entries of the reversed vector
564 Solvers
-
70 Solvers
More from this Author165
Problem Tags
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!