hp 28s - creating nested lists

[Werner]

If you have NDUPN at your disposal, it can be further simplified to:

Code:

\<<
  LIST\->
  DUP 2. + ROLL
  1. ROT START
    SWAP NDUPN \->LIST
  NEXT
\>>

For NDUPN, take any of the following:

Code:

NDUPN
\<< SWAP OVER 1. SWAP START SWAP OVER NEXT DROP \>>
\<< \-> N \<< 1. N START DUP NEXT DROP N \>> \>>
\<<
  -> n
  \<<
    1 2 n
    FOR i
      DUPN i DUP
    STEP
    n - DUP 0 <
    { NEG DUPN }
    { DROPN }
    IFTE
    n
  \>>
\>>

The last one outperforms even the builtin SYSEVAL for large N