HP49-HP50 Lists of combination

[Werner]

My version of DOCOMB. Contrary to the ListExt lib version, intermediate results are not automatically wrapped up in a list, and so the calling sequence for your problem is rather

3: list
2: 4.
1: \<< 4. \->LIST \>>

Code:

@ DOCOMB 265.5 bytes #CC35h
\<<
  ROT 0
  \-> ob L DoC
  \<<
    DEPTH DEPTH ROLLD
    L SIZE
    {}
    { 3 PICK 1 -
      \-> t n
      \<<
        IF n
        THEN FOR s n s 1 - L s GET 1 \->LIST t + DoC EVAL NEXT 
        ELSE FOR s L s GET t LIST\-> DROP ob EVAL NEXT
        END
      \>>
    } DUP 'DoC' STO EVAL
    DEPTH DEPTH ROLL -
    IF DUP 0 > THEN \->LIST ELSE DROP END
  \>>
\>>