Kata > Counterstrings

Here is a 28 character counterstring:

*3*5*7*10*13*16*19*22*25*28*

Here is a 29 character counterstring:

*3*5*7*10*13*16*19*22*25*28*2

Each asterisk is at the position given by the number preceding it.

Generate counterstrings of a given length.