permutations

I would like to make a function based off a number, that arranges the digits 1 through 9 in all possible combinations. Example: 1 2 3 4 5 6 7 8 9 1 1 2 3 4 5 6 7 9 8 2 1 2 3 4 5 6 8 7 9 3 1 2 3 4 5 6 8 9 7 4 1 2 3 4 5 6 9 7 8 5 1 2 3 4 5 6 9 8 7 6 1 2 3 4 5 7 6 8 9 7 1 2 3 4 5 7...

Hello, I have looked through the forum for existing answers to this but can't find a response that I understand enough to modify to my own design. Basically I want to output every combination of a set of numbers. These permutations must include combinations that use only a few of the...

What I am trying to do is find out how many combinations of 5 numbers from 1-9 equal 13 when added up. For example, 1+1+1+1+9=13, 1+2+1+1+8=13, 1+3+1+1+7=13, etc. However, I don't want the combinations that are the same as the ones before such as 1+1+1+1+9 is the same thing as 9+1+1+1+1...