RPL second impressions (HP 28)

[Thomas Klemm]

(06-30-2018 02:37 PM)Gerson W. Barbosa Wrote:  DOERR doesn’t belong in the 28S catalog.

Would the following work then?

Code:

«
  IF DUP 2 MOD
  THEN → n
    «
      IFERR 3 n √
        FOR d
          n d MOD INV
          DROP
          2
        STEP
      THEN
      ELSE 1
      END
    »
  ELSE NOT
  END
»