algorithm help ?

ok this is what i'd like to do.... I'd like to be able to select 19 numbers between 1 and 49 and work out the permutations / combinations of those numbers in groups of six. eg 1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19 results: 1 2 3 4 5 6 1 2 3 5 6 7 1 2 3 6 7 8 and so on..... I have looked around a bit and I believe the way it should be done is in the Linear Reduction method ? ( if this means anything). I haven't had any luck as I'm not that hot when it comes to mathematics do you think you could help ? Thanks for the time Gianni