[code lang="cSharp"]
@"^(//(?<delimiter>.)n?)?(?<data>((?<number>d+)([,n]|k<delimiter>))*(?<number>d+)?)$
[/code]

the only one it does not solve is requirement #8, hence Test_MultipleDelimiterNotation will fail

in the beginning we started from:
[code lang="cSharp"]
(s+)?(?<number>d+)(s+)?(,)?
[/code]

For requirement 8 I would need to add a little bit of logic besides a one line regex in calculator. Hence the calculator should take IParser

[code lang="cSharp"]
public interface IParser
{
IEnumerable<int> Parse(String input);
}
[/code]

before i do i'll setup svn so that revisions can be compared