Number Sequencing, Grouping and Filtering

[flebber]

Hi

I was hoping someone would be able to point me in the direction of
some good documentation regarding sequencing, grouping and filtering
and in which order they should be done.

As a small example it is easy to create the range of numbers 1 to 20.
But if I wanted to group all possible combinations of sets of 4
numbers within this range is there already an in uilt function for
this I am searching the module docs with "number sequencing" and
"number grouping" but cannot find info.

Then if I wanted to refine this results further eg no consecutive
numbers to be contained in sets. Is it best to create all sets and
then filter the sets for things matching this criteria or to set this
condition in a creation. Creating sets and then filtering would soon
become unwieldy with a larger range I would imagine..

An ideas, pointers to docs or better search terms to help me explore
this further would be appreciated.

Thanks Sayth