r: LEXICOGRAPHIC ORDERING

HI all

i have a seemingly simple question.

given a sequence of numbers say, 1,2,3,4,5.

i would like to get all of the possible two number arrangments
(combinations), all 3 number arrangents ... 5 number arrangements
(combinations).

i.e. 

in the 2 number case:

12,13,14,15,23,24,25,34,35,45

any ideas?


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