# Talk:Primes whose first and last number is 3

From Rosetta Code

## Why don't extend the task. Primes in base X ending and starting in digit Y[edit]

So one needs only put together the already best known:

getting primes Sieve_of_Eratosthenes or Primality_by_trial_division

and a base converter like Non-decimal_radices/Convert

05:41, 24 July 2021 (UTC)

- I did add a stretch goal to this (draft) task, but only for the upper limit. I thought the adding of which leading and trailing decimal digit (other than using the specific digit
**3**) would/might invalidate those existing computer programming solutions what made special tests when using a customized range start, and/or a special increment. Certainly, the adding of any radix (base) to be used would add complexity to the requirements and invalidate all existing programming entries. For instance, one option could/would be to search for primes from 3 to 4000-1 by 10. Another customization would be to also check for the leading digit and incorporate special handling so as to bump the range to the next 10, 100, 1000, ... range of integers. -- Gerard Schildberger (talk)

- I do like the idea of extending the (draft) task to find prime numbers that have (both) a leading and trailing (decimal) digit of
**Y**. The upper limit of the range would/should at least be**10,000**. -- Gerard Schildberger (talk) 13:50, 24 July 2021 (UTC)