I'm working on modernizing Rosetta Code's infrastructure. Starting with communications. Please accept this time-limited open invite to RC's Slack.. --Michael Mol (talk) 20:59, 30 May 2020 (UTC)

# Talk:Numbers with prime digits whose sum is 13

## Nice recursive solution

Starting with a set N containing the set of prime digits 2,3,4,5:

1. add each digit in the set of prime numbers to each digit in N (giving 22,23,..,75,77 first time)
2. add any numbers whose digit sum is 13 to the sequence;
3. discard all numbers whose digit sum is greater than 11 from N;
4. repeat until N is empty.

--Nigel Galloway (talk) 14:44, 21 October 2020 (UTC)

Thanks, seems everyone likes that. You can also start with 0 and a simple queue is probably even simpler than recursion. --Pete Lomax (talk)

## output from  Ring  ends too soon

The reference implementation's output (Ring) currently ends at `7,222`. But there are more unlucky numbers. What about `222,223`? --Chunes (talk) 09:28, 29 September 2020 (UTC)

"and sum of them is 13. " --Horst.h
??? Is the sum of the digits of `222,223` not 13? --Thundergnat (talk) 10:12, 29 September 2020 (UTC)
Uups, an unmentioned limit in the program "limit = 10000" that doesn't make sense since 322,222 will be the highest number to test.See also Permutations_with_some_identical_elements.
Maybe a new name for the draft before deletion ;-) --Horst.h

## These are NOT unlucky numbers

Unlucky number have a long established definition and this is not it. (See OEIS A050505.) These are "Integers in base 10 whose digits are all prime and sum to 13". or perhaps "Unlucky digit sums" My question is: what is the significance of the digits being prime? What property makes these numbers "unlucky"? If it is the summing to 13 why wouldn't 168 148 be "unlucky"? --Thundergnat (talk) 10:20, 29 September 2020 (UTC)

## Changes in code

I have changed the code and now is the largest Unlucky Number is 322,222
What do you suggest for new task name?

I'd just call it 'Numbers with prime digits whose sum is 13'. --PureFox (talk) 11:02, 29 September 2020 (UTC)

How can I change task name?
If I could not then please change to:
"Numbers with prime digits whose sum is 13"